We did a full sea trial of the open Nimbus T11 back in March, but this C11 sister model, launched at the 2020 Düsseldorf boat show, also merits a closer look
That’s because the designers have worked hard to make it feel like a separate model rather than just a Nimbus T11 with a lid on it. It starts with a redesigned transom that replaces the T11’s convertible aft bench/sunpad with a dedicated fender rack and a flip-up bench that frees up the cockpit for fishing. There’s even an optional outdoor helm station.
The pilothouse is another fine piece of design with deep wraparound windows, very thin mullions, oversized side doors and four glass skylights overhead. It makes for an exceptionally light, well-ventilated space that stays warm in winter but avoids feeling stuffy in summer. There’s even a full set of front and sidescreen wipers concealed under the wheelhouse overhangs.
The clever seating arrangement converts from a large, c-shaped dinette into two long rows of forward-facing seats for more comfortable cruising, while the helm features two proper suspension chairs.
Below decks it follows a similar layout to the T11 but whereas the open boat has an outdoor galley, the C11 has an indoor galley situated in the lower lobby area. The forward double berth, private mid-cabin and separate heads compartment remain unchanged.
As with the T11, there’s a choice of either Mercury petrol outboard engines and a large cockpit lazarette or Volvo inboard diesels up to twin 440hp D6s. Both should comfortably give top speeds of more than 40 knots thanks to a slippery stepped hull with a narrow entry and heavily flared bow. As an all-year-round commuter that can lend its hand to fishing, cruising or entertaining, it’s an impressively quick, practical and very versatile tool.
We were rather smitten by this new baby of the Nimbus range. Measuring just under 27ft long and with prices starting from £87,142 inc VAT, it’s a natural competitor to the Axopar 28 T-top...
But whereas its rival is a performance-focused day boat with the option of a double berth at the stern, the Nimbus T8 is a proper little overnighter with a good-sized forward cuddy cabin and a separate heads.
It’s blessed with a really safe, well-protected cockpit featuring deep bulwarks, sturdy grab rails and an optional T-top with removable canopies.
The helm is excellent with supportive bolster seats that swivel to face the table and a clean, ergonomic design.
The aft bench also faces both ways and can be laid flat to make a sunpad. It even has a small fridge in its base.
The build quality appears excellent with smooth mouldings, oversized cleats, chunky hinges and top notch fittings, while the stepped hull is said to be good for 46 knots with the largest 300hp outboard engine option.
Hugo Andreae traces the extraordinary story behind the world’s first 100% electric foiling sportsboat, the Candela Seven
For something that looks as cool as the Candela Seven, it’s hard to believe that the starting point was a mathematical equation. But that’s exactly how it came about.
In 2014 a crack team of boffins with experience ranging from fighter jet control technicians to America’s Cup hydrodynamicists, assembled in Stockholm to try and solve a seemingly intractable problem – how to create an all-electric boat with the range and performance to match a petrol one.
The fact is that a 25ft sportsboat uses 15 times as much fuel as a family car, yet pound for pound even the most advanced battery holds 15 times less energy than petrol. To resolve these two conflicting issues, they had to find a way to drastically reduce the energy consumption of their proposed boat.
The mathematical equation they devised looks as dense as a block of concrete but it worked and the result is the Candela Seven – a lightweight carbon-fibre sportsboat that uses active foils and computer-aided flying controls to skim above the waves.
Thanks to their efforts, this next generation foiling sportsboat uses a claimed 75% less energy than a conventional GRP planing sportsboat. To put that in perspective, the Candela Seven requires just 28hp to keep it flying along at 20 knots.
The foiling system accounts for a big part of that saving as it halves the hydrodynamic drag of a normal planing hull. The ultralight carbon fibre construction is responsible for another big chunk of it – even with its 240kg BMW i3 battery pack in situ, the Candela Seven weighs just 1,300kg or roughly half that of a Chris-Craft 27 Corsair.
The final piece of the jigsaw is the super efficient 55kW electric motor, which not only delivers maximum torque at zero rpm but also generates far less waste heat than an equivalent fossil-fuel engine.
To read our full report on the Candela Seven, pick up the July 2020 edition of Motor Boat & Yachting, which is out now.
The Brabus Shadow 900 is based on the all-new Axopar 37, but by the time German tuning specialist has given it the full work over it’s a very different beast.
We enjoyed a brief run out on a prototype of the Brabus Shadow 900 earlier this year and Jack Haines described at as the most effortless 60-knot boat he’s driven.
It’s not hard to see why when you clock those two 450hp supercharged Mercury V8 outboards hanging off the transom then cast your eye down its slender twin-stepped hull.
Carbon fibre inserts, acres of butter-soft Ultraleather, matt black fittings, red engine cowlings and Brabus branding on everything, rams the message home that this is no regular Axopar.
Gullwing doors either side of the cabin make a massive difference to the interior, improving access from the main deck and letting in light and fresh air. Like the Axopar 37, there is the option to have a separate heads/shower room to add some privacy.
The only grumble is the fact that you can’t have a cockpit wet bar and an aft sunpad on deck but in every other respect it’s the ultimate usable super boat – a real Brabus G-Wagon for the sea.
Dorian is one of the few surviving boats to have served in both World Wars, now after a decade-long renovation she’s ready to serve again as a comfortable family motor yacht. Hugo Andreae traces her remarkable history…
Nigel Walters never set out to buy a classic motor yacht, let alone one with a history as long and distinguished as Dorian’s. Until recently any spare time and money that wasn’t devoted to work and family commitments went on his passion for classic British sportscars.
Admittedly, he had grown up around boats, learning to sail in a Mirror dinghy aged nine then graduating to racier Enterprises and Fireballs as a teenager before buying his own Seal 22 pocket cruiser as a young man, but married life, a move to Bedfordshire and the arrival of three children left no free time for boating.
It wasn’t until the mid ’90s, by which time their oldest daughter was 14 and their youngest six, that he and his wife Lyn made the mistake of visiting the Bedford River festival and chanced across a secondhand Sea Ray sportsboat for sale.
“It had a 7.5-litre V8 petrol engine and was totally inappropriate for river use,” says Nigel. “But it looked great so we bought it on a whim.”
It may not have been ideally suited to river life but the family loved it and they ended up keeping it for 10 years despite its increasingly recalcitrant drivetrain.
“It became so unreliable that a weekend without a breakdown wasn’t a proper weekend,” recalls Lyn. But when the driveshaft broke, leaving them stranded miles from home, she finally cracked and insisted they get rid of it.
Lyn then remembered a Sheerline 950 she had fallen in love with at the London Boat Show some eight years earlier, when they had both been indulging their boating dreams, she in the riverboat section, whilst Nigel had wandered off to look at Fairlines and Princesses.
An online search revealed that the 2008 Southampton Boat Show Sheerline was up for sale nearby. Nigel agreed it was better suited to the inland waterways around Bedford than a planing sportscruiser and signed on the dotted line.
They still have the Sheerline today and there the story would have ended were it not for the release of the movie Dunkirk in 2017.
Nigel had recently lost his mother and was looking for a project that would keep his widowed father busy. His original plan was to buy and restore a classic car with him but when that idea fell on deaf ears, he decided to switch tack.
Read the full story of Dorian’s restoration in the August 2020 edition of Motor Boat & Yachting, which is out now.
The Saxdor 200 Sport caught our attention with its bold looks and scarcely believable starting price of £22,158 (inc 100hp engine), but how does it perform on the water?
Very rarely do we feel the need to have two boat testers on the same sea trial, but for the Saxdor 200 Sport we made an exception. That’s partly because the dealer had two models in stock with different engines but mostly because neither Jack nor I wanted to miss out on such an exciting and innovative new craft.
You can make up your own mind after reading this but judging from the two models Saxdor has shown us so far (the 200 and the 32), it looks like being the most exciting new brand since Axopar burst onto the scene in 2014 – and we all know how well that turned out.
Perhaps that’s hardly surprising given that the man behind Saxdor, Sakari Mattila, was also one of the founding partners of Axopar before cutting ties with them and setting up Saxdor as a completely unrelated company. That said it’s not hard to draw parallels between Saxdor and Axopar; they are both Finnish-owned and built in Poland, with edgy styling, vertical bows, outboard engines and competitive prices.
Very competitive in the case of the Saxdor 200. This 20ft sportsboat, complete with a 100hp Mercury outboard engine and a standard spec that includes nav lights and an adjustable windscreen, retails for £22,158 inc VAT on the water in the UK. That’s less than the cost of a hydraulic passerelle on a Princess V55!
So what does your money buy and how has Saxdor managed to make it so affordable? The starting point is a tasty looking twin-step hull with a slender beam of 7ft 6in and an unusually sharp deadrise angle of 22.5° at the transom. This is quasi-race boat territory compared to the 8ft-plus beam and 16-18° you’d normally find on a 20ft sportsboat.
It’s also exceptionally light at 780kg, excluding engine, or roughly 1,000kg with engine, fuel and a few stores on board – again fully half a tonne lighter than a typical 20-footer. That means strong performance and impressive fuel consumption. It also makes it a lot easier to tow, launch and recover using an ordinary family car rather than a hefty 4×4.
Read our full review of the Saxdor 200 Sport in the September 2020 issue of MBY, which is on sale from August 6.
The 2020 generation of the Absolute Navetta 52 isn’t an entirely new boat but there is enough that’s fresh about it to merit a second look
It still uses the original 52ft hull from 2015 but new mould plugs allow for larger, asymmetric side windows. Look closely and you’ll see that the actual window area isn’t quite as big as the smoked glass inserts suggest but they do make space for opening round ports alongside the larger bonded panes.
Other useful exterior tweaks include a boarding gate on the starboard side for easier access from a finger pontoon and a much larger hardtop which, thanks to reversing the angle of the radar arch supports, now stretches further aft to cover the flybridge dinette as well as the helm. Other features like the wide covered side decks, transom-mounted wet bar, huge hydraulic bathing platform and cockpit privacy blind, remain unchanged.
Moving inside the Absolute Navetta 52, the aft window in the galley now drops down quickly and silently to create a neat little bar out into the cockpit while the storage unit to starboard is deeper and easier to access.
In fact, the layout of the main deck is hard to fault. It’s an exceptionally light, roomy and beautifully finished space. Details like the leather-wrapped handrails recessed into the deckhead to form part of a lighting feature are as elegant as they are practical.
Down below, the headroom in all three cabins is exceptional, while the clever offset forward VIP enjoys far more floor space and better views out than is the norm for this size of boat.
Twin IPS600 or 650 pod drives give a modest top speed of around 20-22 knots, but the Absolute Navetta range has always been more about comfortable, relaxed cruising than performance. The only wonder is that they still haven’t caught on in the UK yet.
The third and smallest model in Nimbus’ outboard sportsboat range could actually be the best of the bunch, judging from our lively sea trial...
Of all the W, T, C range of Nimbus sportsboats, the new T8 is the one we were most looking forward to testing. It may be the smallest of the bunch at 26ft 9in (8.15m) long but with up to 300hp hanging off the transom and a very tidy-looking twin step hull, it should also be the fastest and most agile.
Two other factors make it of particular interest to sportsboat fans; it’s considerably more affordable than the other models, with a starting price of £87,142, and it’s trailable. Just.
You’ll need a braked twin-axle trailer and a car with a towing capacity of around 3,500kg but its maximum beam of 2.6m sneaks under the EU’s limit of a 2.3m- wide trailer with up to 30cm overhangs on each side. The Axopar 28, at 2.95m, doesn’t.
So it’s small enough to tow on the road if you want to explore further afield or store it in a shed over winter, it’s powerful enough to pull water-skiers and wakeboarders, yet it’s also spacious enough to serve as both a party platform for day guests and a comfortable overnighter for a couple thanks to a good-sized cuddy cabin with a separate heads compartment and a permanent double bed.
It sounds almost too good to be true but does it actually deliver as much as hoped out at sea?
Read our full review of the Nimbus T8 in the October 2020 issue of MBY, out September 3.
Former Mini, Ferrari and McLaren designer Frank Stephenson shares his passion for a very special Thames slipper launch...
Frank Stephenson is not your average boat owner. He designs cars for a living. Rather special ones.
His CV reads like a roll call of Top Gear’s greatest hits. He designed the infamous wing for the original Ford Escort Cosworth, styled the first X5 for BMW, reinvented the Mini as a 21st century style icon, was poached by Ferrari to oversee the F430, was seconded to Fiat to pen the new 500, moved to McLaren to fashion its latest range of hypercars… the list goes on but you get the gist.
In short, he’s arguably the world’s most successful car designer. And yet, what does he choose to drive at the weekend?
Some of the many successful cars which Stephenson has designed
A classic Thames slipper launch built for him by the legendary Peter Freebody yard, which he keeps on the river just yards from his home near Henley, Oxfordshire.
For a boy who grew up in Morocco, raced motorcycles as a teenager and spent most of his adult life roaming the world penning 200mph supercars, it seems an oddly sedate choice.
And yet for Stephenson the boat provides the perfect antidote to a life lived at breakneck speed, a haven where he can relax with his wife Linda and enjoy the quieter side of life.
Stephenson at the helm of his personalised slipper launch, Riverbreeze
Like many boat owners, he grew up with boating in his blood. His father worked for Boeing and when he and his young family were posted to Casablanca, on the Atlantic coast of Morocco, he set about building a boat for them all. Stephenson remembers it only too well.
“It was my first memory of physical pain,” he recalls. “I was 4-5 years old and was sitting under the boat in my father’s workshop. I was looking up at the light through the hole he had made for the shaft to go through when he inadvertently blew the sawdust straight into my eye. I had to go to the hospital for an eye wash!”
Not that the experience put him off boating. Far from it. He still credits his father’s eye for detail and his hands-on approach to craftsmanship for sowing the seeds that led to his own career success.
Photo: Tom Mannio
“I loved watching him build that boat. Everything had to be perfect, right down to the grain of the wood and alignment of the screws, even in places you couldn’t see because he’d still know if it wasn’t right. That same philosophy must have rubbed off on me. I can never let go of a design until every last detail is correct.”
The boat in question was a home-built sportsboat called Missile. It was powered by an ex-military Chevrolet V8 engine and still tugs at Stephenson’s heartstrings when he reminisces about it. “I have so many fabulous memories of that boat – the smell of the wood, the glow of the varnish, the sound of the engine. It has never left me.”
After a spell in Turkey the family moved to Spain where his father set up a car dealership with the help of his Spanish brother-in-law.
Frank at his Henley home
After leaving school, Stephenson joined the business running the body repair side of the company while his brother focused on the mechanics. “I guess that’s where my love of cars really started,” he explains.
It wasn’t to last though, as a chance meeting with a Spanish friend and motorcycle racer introduced him to the high-adrenaline world of motocross racing. Stephenson proved a natural and at the age of 17 won the national junior title, rapidly moving through the ranks to compete in the senior world championship.
A life less ordinary
“It was a heady time for me, I was getting paid to race bikes, travel around the world and lead the most amazing lifestyle. But after four years of competing my father sat me down and told me it was time to stop. I was regularly finishing in the top 10 but that wasn’t good enough for him. He said you have to win or it’s not worth it. Nobody remembers second place.”
Stephenson draws inspiration from the natural world to design supercars for the likes of McLaren
It was a harsh lesson but one which Stephenson took on board and still lives by to this day. He’d always enjoyed drawing cars in his spare time and when he read about a design college in Pasadena, California that specialised in car design he sent in a portfolio of 12 drawings and applied for a place.
“I arrived in the summer of 1983 to find 29 other students on the same course. On our first day we were told that we were the top 1% of more than 3,000 students who had applied but that the course was so challenging only 10 of us would make it through. In the end only six of our intake lasted the full four years.”
Ford approached Stephenson halfway through the course and sponsored his tuition fees on the understanding he would join the company on graduating. He was sent to Germany to work for Ford of Europe and was immediately put to work designing the rear wing for the first Ford Escort Cosworth.
He took inspiration from the Red Baron’s Fokker DR1 triplane to create the massive rear wing that helped make the ‘Cossie’ an instant hit with fast Ford fans and secured it the dubious title of the UK’s most stolen car.
From there he moved to BMW where he was asked to interpret what a BMW Land Rover would look like. He was given just six weeks to create a full-scale model with the help of a specialist plaster modelling shop in Italy. He designed the basis of the X5 on the two-and-a-half-hour flight down to Milan and spent the rest of the time creating it with his team of Italian craftsmen.
However, it was his work on the new Mini that really made his name. Fifteen of the world’s top car designers were invited to submit their ideas to the BMW board in a competition to find the right successor to Sir Alec Issigonis’s iconic 1959 people’s car.
Mini marvel
“We were given a month to design it and five months to build the model so instead of trying to design the final car straight away I spent the first week designing what a 1969 version of it could look like. The second week I evolved that design for 1979 and so on until in week four I designed one for 1999. It was the only way I could ensure the new Mini was a true genetic successor to the original.”
Stephenson talks car design with Jay Leno for the DVD about his life story
Stephenson’s design won the unanimous support of the BMW board and went into production in 2000, becoming an instant hit around the globe. His career took off from there, attracting the attention of Ferrari in 2002, where he headed up the in-house design team for the F430 and FXX ‘Super-Enzo’ as well as the Maserati MC12 and new Fiat 500 city car.
However, it was his move to McLaren in 2008 to help Ron Dennis turn the hugely successful Formula 1 team into a manufacturer of road-legal supercars that put him back on the path to boat ownership.
Way back in 1996 he’d met his future wife Linda at a motorsport awards ceremony at the Dorchester hotel in London and now, after years of maintaining a long-distance relationship while he travelled around the world with his job, this was his chance to move to the UK and be with her permanently.
She had a house near Henley and with McLaren being 28 miles down the road in Woking, things couldn’t have worked out better. On their regular walks along the river he found himself drawn to the elegant slipper launches that emerged from the shed at Peter Freebody’s eponymous yard.
“I went down to see Peter every weekend. I’d sit on a bucket in his workshop with him and talk boats long into the evening. He was the real deal, a true eccentric but a master of his art. I think he knew from my own background that I appreciated what he was doing.”
The grain of the mahogany planks helped persuade Stephenson to commission a new 30ft Slipper launch
A secondhand 25ft slipper launch came up for sale that had previously been owned by a Swedish cinematographer, which Stephenson couldn’t resist.
Comfy slippers
“I bought it and kept it for a couple of years but after a while I started seeing an even more elegant 30-footer on the river. I couldn’t bear the idea that mine was somehow the lesser model. As ever I wanted the full-works version.”
Sadly, Peter Freebody passed away in 2010 but by then Stephenson had got the boating bug in a big way. In 2011 he commissioned his own brand new 30ft slipper launch, the first since Peter’s son and daughter had taken over the yard.
Stephenson’s eye for perfection found an ideal match in Freebody’s obsessive craftsmanship
“As soon as I saw the planks of mahogany they were planning to use for the next build I had to have it,” recalls Stephenson.
“It was the grain of the wood that sold it to me.” Stephenson would drop in most mornings before work to check on the build and give his input into the design and layout of the interior.
As a technophile he wanted it to have all the latest mod cons including an electric pod drive motor. “There’s a speed limit on the river and an electric motor has the advantage of being almost totally silent. You can glide along listening to the birds sing and the wind rustling through the trees.”
Instead of the usual Lloyd Loom chairs, Stephenson specified a leather bench for the helm and a sociable horseshoe of seating that wraps around the aft end of the cockpit. He even asked Richard Freebody to match the colour of the leather to the collar of the couple’s favourite dog.
The leather was matched to his dog’s collar
“After a hard week’s work it’s the perfect way to relax,” adds Stephenson. “We load up a picnic lunch, a couple of my favourite cigars, the two dogs and set off along the river to Marlow taking time to admire the wildlife and beautiful riverside homes en route.”
Even when the weather isn’t amenable he likes to wander down to the boat and wipe a chammy over it, taking time to admire the 15-20 coats of varnish that keep its decks gleaming – there isn’t a specified number, Richard Freebody says they just keep on adding coats until they are happy with it.
Chasing perfect
As for Stephenson, he has now moved on from McLaren to set up his own design studio, creating everything from children’s car seats to autonomous flying vehicles. He’s already led such a full life that Netflix has made a film about him called Chasing Perfect, which explores his complicated relationship with his father and his own relentless quest for perfection, including some fascinating insights into car design with the help of US chat show host and avid car collector Jay Leno.
As for whether he would ever design a boat from scratch, he just nods knowingly and says, “Watch this space.”
First published in the September 2020 issue of Motor Boat & Yachting.
MBY editor Hugo Andreae takes his first ride on the Kawasaki SX-R stand-up Jet Ski to see if this pumped up speed machine really is the next big thing in motoryacht toys.
Hugo tries hard to look like he knows what he’s doing – nobody is fooled! All photos: Hugo Andreae
Being a 52-year-old bloke, I’m not usually one for paying much attention to instruction manuals but having never attempted to ride a stand-up jet ski before, I thought it might be worth a quick peek. I’m very glad I did because page 1 of the Kawasaki SX-R manual contains some rather important advice to wear wetsuit bottoms or some other form of protective clothing.
The consequences of ignoring this are also spelled in alarmingly anatomical detail. The precise wording is: “As a result of falling into water or being near the jet thrust nozzle, water can be forced into body cavities such as the rectum.”
Not the kind of thing you usually expect to read when getting to know a new toy but it certainly caught my attention. If this seems a little over dramatic perhaps it’s worth a quick reminder of what we’re dealing with here and why the readers of Motor Boat & Yachting should be interested in a jet ski in the first place.
Hugo sizes up the beast he’s got to test drive…
Jet ski evolution
There are two kinds of personal water craft (PWC) – the original stand-up style like this Kawasaki SX-R Jet Ski and the larger sit-down style such as the Seadoo Spark and Yamaha Waverider. It is these sit-down models which now dominate the market, to such an extent that in 2011 Kawasaki discontinued its stand-up range altogether. The jet ski name lived on as a generic term to describe any form of PWC (it’s actually a Kawasaki registered trademark) but not the product itself.
For six years the line lay dormant until in 2017 Kawasaki launched a brand new Jet Ski called the SX-R – a pumped-up, pimped-up, stand-up model with eye-bleeding graphics and a monstrous 1,500cc four-stroke engine.
It is the 2020 version of this model which Boats.co.uk has invited me to test over the course of my week-long summer holiday on the basis that the usual two-hour blast won’t give me enough time to get the hang of it.
These guys know a thing or two about motor boats, being an international dealer for Princess Yachts and one of the largest used boat brokers in the UK, and the reason they’ve just taken on the import rights for Kawasaki watercraft is because they reckon the SX-R is going to be the next big thing in motoryacht toys.
The theory goes that for less than the price of a Seabob, you can buy one of these 60mph rocketships, which unlike the bigger sit-down PWCs, is small and light enough to sit alongside the tender on many larger cruising boats, and a whole lot more fun to boot.
Standing start
It’s a reasonable enough theory but it does rely on the owner possessing two things – a reasonable degree of rider skill and a wetsuit. I only have the latter. Still, what could possibly go wrong? Other than that whole body cavity thing…
Bespoke road trailer has alloy wheels and matching colour scheme
A more in-depth study of the specifications reveals a few other minor concerns. That new engine chucks out 150hp at 7,500rpm yet the Kawasaki SX-R is barely 8ft 6in long and weighs just 250kg, making it the fastest accelerating stand-up production PWC ever made. Not altogether surprising given that its power to weight ratio of 600hp per tonne is considerably higher than a McLaren 720LT supercar’s (563hp per tonne).
Rather more surprising is that it’s not fully stable until its planing. Oh, and it doesn’t have a neutral gear; as soon as you start the engine you’re off. I don’t know about the rest of you but I’ve always been a big fan of neutral. I find it really helps with the whole ‘not crashing into things’ routine.
Feeling more than a little apprehensive, I back the equally blinged-up road trailer down the slipway and ease the SX-R off its rollers into the water. It may be light by PWC standards but a quarter of a tonne still takes some manhandling – a hydraulic bathing platform or crane is a must for easy launch and recovery from a boat.
The latest SX-R Jet Ski has a top speed of well over 50 knots – if you’re brave enough!
In shallow water, it’s easy enough for me to keep one foot on the ground while kneeling on the soft rubber deck with the other (in deeper water you need to be dragged behind it a little way before pulling yourself onto it). I slip the kill cord over my wrist, say a last minute prayer and stab the little red starter button.
The engine bursts into life and immediately starts to pull me forward. Even at idle I can feel the thrust of the water jet pushing at my thigh so I raise my other leg and kneel on the platform with my feet hanging over the edge. I’m relieved to discover that it’s actually quite stable and easy to steer like this, even at low speeds, so long as I keep my weight low.
It’s only when I try to stand up that things get interesting. Nor can I overestimate just how much power this thing has. The sensitive finger throttle needs only the gentlest of squeezes to unleash the kind of acceleration normally only experienced by astronauts and human cannonballs. Even after seven days’ use, I still couldn’t swallow enough brave pills to attempt a flat-out run.
No instruments, just a warning light for fuel and engine
Big boys’ toys
On the plus side you don’t need to be travelling at Mach One to have a lot of fun on the Kawasaki SX-R. I’ve always found sit-down PWCs to be enormously enjoyable for 20 mins but then I’m ready to give it back. After doing the going really quickly thing and the whizzing round in circles thing, that’s it, I’ve had enough. Not with the SX-R, even at quarter throttle it’s both entertaining and challenging, particularly when it comes to turning.
I’m a reasonably competent windsurfer and mono-skiier but mastering quick turns on the SX-R while standing up is a real brain scrambler. It sounds simple enough – turn the handlebars, lean into the bend and apply throttle – but selecting the right amount of each at the right time is considerably trickier than you might think.
Too much or too little of any one variable at the wrong time and you’ll end up face down in the water. And believe me there is nothing more humiliating than swimming forlornly after a very swanky, very green, very shiny jet ski in front of a beach full of people. The kill cord stops the engine quickly enough but at 30 knots or more the SX-R takes a while before it comes to a halt. And laughter carries a long way across water.
Hugo’s 17-year-old son shows Dad how it should be done
On the other hand when you get it right and carve a perfect arc across a sparkling green sea with your elbow trailing inches from the surface you look and feel like a God. Apparently.
Once or twice I almost got it right, or at least right enough to want to keep on trying to master it, which is why I also found it so much more engaging than a sit-down PWC. The downside is that there isn’t room to take anyone else with you nor can you stop and bob around on board it once you get somewhere.
There isn’t even a dry storage locker for a drink and a sandwich let alone an anchor and there’s only a 23-litre fuel tank. There aren’t even any dials or gauges, just two warning lights to show ‘engine running’ and ‘low fuel-level’. As Boats.co.uk rightly surmise it is a toy; an extremely fast, exhilarating and strangely addictive one but still a toy.
The fact that it’s nothing like as easy to master as a Seabob or PWC is both its greatest asset and its greatest flaw. If you aren’t prepared to put the time in to learn a new skill or haven’t got the appetite or physicality to get stuck in, you might as well buy a Seabob and a nice pair of swimming trunks.
If you have, then there’s a lifetime of fun to be had mastering the SX-R. Just don’t forget the wetsuit.
A radical new foiling hull design claims to combine the efficiency of a trimaran with the space of a monohull — Hugo Andreae takes a look at the world’s first trimonoran motoryacht
Speeds are higher and fuel efficiency is also much improved
Award-winning Turkish yacht designer Baran Akalin has combined forces with Dutch engineer G. Jelle Bilkert to create what they describe as the world’s first ‘trimonoran’. As the name suggests it is based on a ground-breaking new hull design that claims to offer the efficiency and stability of a trimaran with the speed and volume of a monohull.
Instead of three slender vertical hulls linked by spars or a beamy main deck, the two outer hulls fan out at an angle from the central hull like the segments of an orange. These are linked below the waterline with hydrofoils to create the necessary lift for planing without the associated drag and unforgiving ride of a big, beamy monohull.
The idea was originally drafted by Dutch naval architect G. Jelle Bilkert some time ago but has now been refined, developed and tank tested with the aid of Dutch government funding into a fully patented production concept by Dutch company AnwigemA BV.
Budding Turkish yacht designer Baran Akalin, who won a design award last year for his futuristic steampunk superyacht concept, saw its potential as the basis and has further developed the idea into a striking new luxury motoryacht concept named Escalade.
Tank testing of the scale model proved its potential
Fast and efficient
The benefits of this new low drag design are said to include speed gains of up to 30% over a conventional monohull, excellent stability both under way and at rest, large deck and hull spaces and superior fuel efficiency at cruising speeds leading to a greater range.
The principal is much the same as a trimaran in as far as the slender central hull generates less drag than a single beamy monohull design and slices cleanly through waves for a softer more efficient ride. The two outer hulls then provide the lateral stability as well as the extra volume and deck space needed to house the accommodation.
However, unlike a conventional multihull, it doesn’t come with the penalty of an excessively wide beam that makes it hard to fit into marina berths, nor the small planing surfaces that require huge amounts of power to generate enough lift to make it plane.
The key to this new trimonoran design is the addition of two foils linking the front and stern sections of the outer hulls. These not only provide lift but also reduce drag to enable the kind of planing speeds not normally possible with this size and style of yacht.
Another break from tradition is the adoption of a hydraulic link to transfer power between the engines and the propellers rather than a conventional shaft.
This allows the engines to be positioned amidships to keep the weight as low and central as possible while the propellers are mounted on the aft foil to keep them immersed at all times. The only physical link between the two are the high pressure hoses which feed hydraulic fluid from the main engines to the small hydraulic motors and shafts in the foil. Sealegs amphibious boats use a similar system to feed hydraulic power from the petrol generator mounted under the helm seat to the folding wheels on the transom.
Size not compromise
Akalin’s current design for Escalade is based on an LOA of 82ft (25m) with a beam of 32ft 8in (10m). This is almost double the width of a comparable monohull such as the Princess 82 (18ft 10in) but still usefully slimmer than a similar length of powercat such as the Sunreef Power 80 (39ft 4in).
Vast main deck makes the most of its 32ft beam with central seating on a raised plinth
This length-to-beam ratio creates enough volume on the lower decks for four cabins and four bathrooms including a large master suite in the bow and an additional two-person crew cabin. However, the big wins are on the main and flybridge decks, both of which benefit from the extra floor space enabled by that 32ft beam.
The main deck incorporates a large open plan living area with a galley on the starboard side and a lounge area to port, in the middle of the yacht on a slightly raised plinth is a central seating and dining area with uninterrupted views out both sides. Doors out to the side decks as well as the cockpit encourage an easy flow of people and air through the yacht. The styling of the interior is the work of British designer Celia Sawyer.
Access to the flybridge is via a central staircase which passes under a glass-bottomed jacuzzi that allows light to filter down into the cockpit below as well as a unique view for its occupants of the wake trailing out behind. Multiple sunpads on the flybridge, in the aft cockpit and on the foredeck ensure it’s every bit as luxurious as a conventional monohull while its futuristic looks are a far cry from the rather dumpy looks of some multihull designs.
Although only a concept at this stage Akalin is confident Escalade could be turned into a viable production or semi-custom superyacht at a price that would allow it to compete with monohulls of similar volume.
First published in the October 2020 issue of Motor Boat & Yachting.
Is it possible to build a fast boat that never slams? Hugo tests the first British-built Rafnar 850 RIB to find out...
Like perpetual motion or alchemy, the dream of a fast boat that never slams has remained as elusive as the lost city of Atlantis. Boat builders, naval architects and scientists have spent thousands of hours trying everything from fins and foils to wave piercers and air keels to crack this maritime conundrum with varying degrees of success.
But of all the ideas we have come across at MBY, one of the most promising comes not from a highly qualified marine engineer with a brain the size of a basketball but a wealthy Icelandic amputee who made his fortune designing prosthetic limbs. When Össur Kristinsson’s search for a fast boat that he could helm pain-free through the rough seas around Iceland proved fruitless, he decided to build his own.
In the way that only a man of his focus and determination could, he threw himself into reading and researching everything he could about hull design, including the work of a relatively obscure 19th century Swedish inventor and boat designer called Fredrik Ljungström.
His arc-of-circle theory purported that the more gently you ask the water flowing around a hull to change direction, the less disturbance and drag it would create. By the same logic, the constant curve of an arc was likely to be the most efficient shape for a boat’s hull and keel.
At the time, Ljungström only applied this thinking to sailing boats but Össur Kristinsson saw potential in adapting it for power boat designs to reduce slamming without the simultaneous loss of speed and efficiency associated with conventional displacement or semi-planing designs.
Seventeen years and a rumoured €45 million of investment later, including copious tank testing and live sea trials with the Icelandic Coastguard, the Rafnar OK hull was finally ready for production.
MBY tried one of the first prototypes back in 2015 but only recently have we had the chance to conduct a full test of a production-ready Rafnar 850 RIB in UK waters.
Read our full review of the Rafnar 850 RIB in the December issue of MBY, out November 5.
Aerial drones have become a popular way for owners to capture unique photos and videos of their boats but could PowerVision’s latest marine drone be an even better option?
If it’s true that “he who dies with the most toys wins” then surely the PowerDolphin would propel you right to the front of the queue. As boys’ toys go, it ticks all the key boxes: fast, tick; cool, tick; expensive, tick; pointless, tick.
OK, maybe that last one is a bit harsh but despite the manufacturer’s best efforts to sell it as everything from a safety aid (apparently it can drag a lifejacket to a casualty) to a fishing tool (you can tow a line and drop bait), it’s hard to see any boat owners using it for anything other than whizzing around the bay taking the occasional video and photograph.
To all intents and purposes the PowerDolphin is a waterborne drone that scoots around on the surface of the sea with a camera in the nose cone that can point up or down to capture footage above or below the water. It’s an impressive-looking bit of kit that comes in the kind of expensive looking box that Apple would be proud of.
It also packs some pretty advanced tech including a waterproof wide-angle 12 megapixel camera that can shoot 4K video, mounted on an articulated arm that can swing through 220°. The drone itself is designed to float, although it can briefly dive underwater before its buoyancy gets the better of it.
A powerful 64Wh lithium ion battery drives a pair of caged propellers, giving you 20 minutes of ‘flying’ time at its maximum speed of eight knots or 2.5 hours in displacement-only ‘underwater’ mode.
The remote controller has its own in-built rechargeable battery and a mount for holding your smartphone that links wirelessly to the PowerDolphin’s camera via the PowerVision app so you can see what you’re filming in real time as well as recording it on a Micro SD card mounted in the drone itself.
It’s a bit of a fiddle to set up and get everything connected (hence my scepticism about its usefulness as a safety aid) but the flashing LEDs on the PowerDolphin’s ‘wings’ change colour to show you when it’s good to go.
Even then a built-in sensor stops the propellers turning until it’s in the water – sensible from a safety point of view but rather disconcerting having to launch it without being able to test that it’s actually working.
If eight knots doesn’t sound terribly exciting on paper, it certainly doesn’t feel that way when out on the water. The small scale of the PowerDolphin seems to exaggerate its speed as it zips around the bay sounding like a demented wasp.
An above water photo taken by the PowerDolphin of Hugo’s boat
Like any remote-control vehicle, it takes a bit of practice getting used to the steering and throttle sensitivity and I certainly wouldn’t want to risk it in a crowded bay. It weighs a couple of kilos and at eight knots it carries a fair bit of momentum, as I found out when it bounced off my own boat’s hull during an ill-judged fly-by.
The auto-return feature also needs using with care as it doesn’t take account of obstacles in its path such as wooden mooring posts – oops again!
While a waterborne camera sounds like a fun idea, the reality is that unless the sea is incredibly flat, any footage you shoot tends to be pretty jerky. The underwater shooting mode has more potential, especially if you boat in tropical waters. Cruising slowly over a shallow coral reef streaming live footage to guests on board the mothership would be pretty cool. The best I could manage was a brief glimpse of the sea bed off the beach in Sandbanks.
A shot of the seabed off Sandbanks taken by the PowerDolphin
In reality the PowerDolphin seems to me more like a glorified remote-control boat than a useful aid to photography or boat safety, which may make the price a little hard to swallow for all but the most committed toy collectors.
For the rest of us, one of PowerVision’s aerial drones might be a better way to capture memorable photos and video of boats.
Value: 2/5
MBY rating: 3/5
RRP: £695
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A new type of ultra-tough ceramic coating claims to protect your boat against everything from salt and sunlight to bird poo and red wine. Hugo Andreae puts Ceramic Pro to the test...
Family and friends enjoy the Karnic’s sparkly new Ceramic Pro finish
Some people actively enjoy polishing their boat day in, day out. I’m not one of them. Life is too short and I’d rather spend the time using my boat rather than cleaning it. The fact that it sits on a swing mooring all summer without access to a fresh water hose doesn’t help either, so other than a quick slosh down with a bucket of seawater at both ends of the day, that’s as good as it gets.
To be fair, my poor little Karnic 2250 has coped remarkably well with my shameful regime of neglect. It’s over 14 years old now but thanks to a vinyl wrap in 2014 and reupholstered cockpit seating in 2016 it could pass for a boat half its age. It’s only when you look closer that it’s true years start to show.
The white gelcoat on the foredeck and cockpit coaming has lost its shine and now has a slightly porous matt finish that feels almost chalky to the touch. The stainless steel guardrails are scratched and lightly pitted with brown rust stains around the stanchion bases.
Article continues below…
Rik Breur’s invention challenges traditional antifouling
MBY editor Hugo Andreae explains why anti-fouling your boat is so important and how to do it right
And all along the waterline, especially on the twin bathing platforms, constant immersion in the sea has left a brown scum line that no amount of Y10 gel seems to remove. Even the Suzuki DF200’s engine casing has lost its sparkle, although the internals seem as robust and reliable as ever.
So when Chris Dell from Ceramic Pro UK offered to show off the company’s range of ceramic-based nano coatings that claim to protect every inch of the boat’s exterior for up to three years and drastically reduce cleaning times, I didn’t have far to look to find a suitable demo boat.
Hard as nails
Unlike conventional polishes that rely on some form of wax or sealant to create a temporary gloss that gradually washes or fades away over time, Ceramic Pro claims to use a nanoceramic coating that bonds with the substrate at a molecular level to form a permanent clear coating that can only be removed by abrasion.
The white gelcoat had lost its glossy shine
According to its sales literature no detergent or compound can break it down through chemical processes alone. It goes on to say that once this clear ceramic coating has cured, it becomes so tough that it can withstand scuffs and scratches that would damage softer gelcoat. Even regular gloss paint has a hardness rating of 4H whereas Ceramic Pro has a 9H rating.
It’s also super-hydrophobic causing water to bead and run off. In fact, it leaves such a smooth surface that weed and barnacles will struggle to get a grip on it, leading to claims that it can be used as a form of antifouling on bare gelcoat and may even reduce fuel consumption in the process. Last but not least it contains silicone and titanium dioxide to block UV damage and leave a lasting gloss.
As well as protecting gelcoat, Ceramic Pro Marine can be used on paint, stainless steel, rubber and plastic, while other specialist Ceramic Pro products cater for fabrics, glass, RIB tubes and even teak decks (to prevent them staining or going grey). So much for the theory but how does it work in practice on a tired-looking 14-year-old boat?
The level of detailing verges on OCD
All in the prep
I was rather surprised to see an entire convoy of Ceramic Pro vehicles turn up at my boatyard at 08:00 one June morning, especially when no fewer than five people spilled out of them. I was even more surprised to find that they were still working on my boat at 20:00 that evening.
This is no mere cut and polish job, it’s a full on top-to-bottom detailing service that leaves no cushion or locker lid unturned. I thought it was a joke when one of them pulled out a toothbrush to start scrubbing around the stanchion bases – not a bit of it, cleaning Ceramic Pro-style is a serious business that requires a different tool and product for every crack and crevice.
Even areas of the boat that never get seen, such as the underside of the pulpit and bathing platforms, were meticulously scrubbed, cleaned and treated with Oxacylic acid to remove rust and algae stains, while fittings such as the cover poppers were removed to enable easier access for the rotary polisher.
Removing rust stains around the stanchion bases
With a product as permanent as Ceramic Pro there is no point applying it until the surface is completely clean or you’ll simply lock in the dirt that’s already there. Although my boat’s gelcoat looked superficially clean, it was covered in tiny micropores where dirt could settle.
Every single surface had to be rinsed and washed to remove this dirt, then polished back with cutting compound before a final degrease and wipe down to remove any residual chemicals. Only then could it be treated with Nano Primer to fill in the micro-pores and Ceramic Pro Marine to seal it, the hardest of the various finishing treatments available.
On my boat at least 80% of the time was spent preparing the various different surfaces and substances, whereas on a newer or better maintained boat this phase would be a much quicker process.
Every inch of exposed GRP had to be cut back
Shine on
There are two options for applying the final coat; both involve gently wiping on an even layer of Ceramic Pro Marine with a soft sponge or the slightly thinner Ceramic Pro Brava but then you can either leave it to cure like a clear lacquer or buff most of it off for an even smoother, glossier finish.
The extra thickness of the former provides longer-lasting protection but on close inspection leaves very slight streak marks in the surface, the latter provides the ultimate flawless finish, although if you really want to go to town you can keep applying and buffing off more layers to build up its thickness.
Given my lackadaisical approach to cleaning I opted for the former but even with this marginally less perfect finish, it left my boat looking like a different beast. It really could have been a brand new boat. They also coated my cockpit seat cushions with Ceramic Pro Care + fabric treatment and demonstrated its effectiveness by pouring a bottle of Coke over it! A quick wipe and it looked as good as new.
The cockpit looks as good as new after treatment
Lasting impressions
Having lived with it over the course of the summer season I can now confirm that it has not only stood the initial test of time (three months and counting) but it has made my minimalistic cleaning routine even easier. Now when I throw a bucket of seawater over it it runs straight off the windscreen and foredeck without leaving countless salt stains behind.
I can even confirm that around the waterline where a layer of slime and barnacles had started to grow I could wipe them off with just a gentle rub of my thumb, although it has left some staining. I still question whether it will prove as effective as conventional biocide antifouling or a slipperier silicone-based fouling release system, but Ceramic Pro is carrying out further trials on a new Cobra RIB and static Aquadock to see how well it performs as an antifouling.
The cost of the treatment varies significantly according to the amount of preparation and the number of different surfaces to be coated. To treat a brand new 8m RIB including the entire hull, tubes, decks and seats would cost in the region of £2,800 to £3,500 plus VAT, while treating just the hull and decks of a secondhand Fairline Targa 34 in good condition would be around £3,500 plus VAT.
Ceramic Pro coating should keep it looking this good for the next three years
Ceramic Pro’s argument is that it will immediately add more than that to the value of the boat and will ensure it stays in better condition for years to come as well as reduce the time spent on cleaning it.
I will continue to report on how it performs on my boat over the next three years with regular updates in ‘Our Boats’ but for the moment I am just as impressed with the Ceramic Pro team’s astonishingly detailed cleaning service as I am with its products. If the treatment lives up to the same high standards and delivers on its claims, it could prove a boon for perfectionists and lazy boat owners alike.
First published in the November 2020 issue of Motor Boat & Yachting.
The Motor Boat Awards are going virtual in 2021 and we need your help to decide who should win our coveted Customer Service Award sponsored by Nautibuoy
What a strange year it has been! If someone had told me this time last year that we’d all be prisoners in our own homes, barred from seeing friends or nipping out for a pint let alone visiting our own boats, I’d have dismissed them as a crackpot. And yet when it happened, we groaned and we grumbled but for the most part we did what was asked of us for the greater good.
Arguably, as a magazine we didn’t have it as bad as many marine businesses, which had to shut up shop, but without boats to test or shows to visit we had to find more creative ways of filling the pages.
I mention this because we’re announcing the finalists for the 2021 Motor Boat Awards in the next issue of MBY (out December 3) and due to the smaller number of boats we were able to test, means we’ve also reduced the number of categories from 11 to 8.
However, the one category which takes on one even more significance than usual is the Customer Service Award sponsored by Nautibuoy. Given the tough times they’ve already been through this year and the added expense of running a business with Covid restrictions in place, they need your support more than ever.
So please take the time to nominate any UK-based marine business (brokers, dealers, marinas, engineers, retailers etc.) that has gone out of its way to look after you or your boat.
Just email me at mailto:mby@futurenet.com with the words ‘Service Award’ in the subject line and a brief description of what they did to merit your nomination before December 16.
The winners will be announced in a virtual ceremony on 19 January and in the March 2021 edition of Motor Boat & Yachting.
The Motor Boat & Yachting 2021 Customer Service Award is sponsored by Nautibuoy Marine.
From stalwart of the sea to sporty SUV, pilothouse boats are encountering something of a revolution but the Hydrolift X-27 may be the most extreme example yet.
Pilothouse boats never used to be the sportiest of craft. Practical, yes. Seaworthy, yes. Good value, usually. But sporty? Not so much. However, change is afoot…
In much the same way that boring MPV cars morphed into sportier SUVs, so wheelhouse boats are evolving into something altogether more dynamic. Axopar went a long way to changing perceptions with its 28 Cabin and 37XC but now Hydrolift has taken it one step further with the most extreme sports utility vessel yet.
Not only is its latest craft called the X-27 SUV but with a claimed top speed of more than 70 knots (yes, you read that right the first time) the emphasis is firmly on the sports part of the acronym.
Wisely, Hydrolift UK decided to order its test boat with a single 300hp Mercury Verado outboard rather than the twin 250hp or single 450R options but the spec still makes for tantalising reading.
The slender twin-step hull has a knife-like deadrise angle of 24° while its sandwich construction keeps the weight down to 2,300kg. The hull is the work of Norwegian powerboat racer and Hydrolift founder Bard Eker and is shared with the S-26 open sportsboat we tested last year. Impressive as that boat was, the X-27 SUV is more intriguing, partly because it can be used all year round and partly because it doesn’t look like it should be capable of those speeds.
Whereas the Brabus Shadow 500 Cabin screams performance from every pore, the Hydrolift X-27 SUV looks more like a run of the mill sportsfisher in the mould of a Jeanneau Merry Fisher or Finnmaster C8. Step on board and there are clues to its true intent; even with the pilothouse offset to starboard in order to leave a walkway down the port side, the X-27 feels narrower than most SUVs.
And that deep vee means it’s more sensitive to weight too – in fact the whole test boat leaned slightly to starboard at rest, presumably due to that offset pilothouse. The long drooping bow with its squared off snout and inset spotlight also hint at something more purposeful than the usual tall stubby bow needed to maximise space down below.
In fact, with no access to the lower deck from the pilothouse, you could be forgiven for thinking that overnighting wasn’t an option on the Hydrolift X-27 – we’ll come to that later.
Then there’s the helm with its deep bucket seat, designed to support your hips whether standing or seated, and sporty three-spoke wheel. The really quick ones even have racing style controls with separate levers for the gears and throttle. It all speaks of a more driver-focused boat than the average pilothouse craft.
Read our full review of the Hydrolift X-27 SUV in the January 2021 issue of MBY, out December 3.
Is there more to the eye-poppingly beautiful Comitti Breva 35 than just good looks? We find out with a blustery test in the Solent...
Owning a boat as beautiful as this Comitti Breva 35 must be a bit of a double-edged sword; on the one hand it’s very flattering that so many passers-by stop to admire it, on the other hand it’s rather frustrating that the first question they’re likely to ask is whether it’s a Riva.
The short answer is no, Comitti is a completely different yard that has been building boats on the shores of Lake Como since 1956. The long answer is that Comitti is an even more exclusive brand, building a limited range of elegant open sportsboats from 25-35ft, including a handful of classic wooden craft that can trace their origins back to the 1950s and 1960s.
That tends to shut up most casual passers-by but the more inquisitive among them might still go on to ask whether it’s as good as a Riva. And that is the question which we are hoping to answer today.
The good news is that we have the perfect opportunity to find out, not on a mirror-smooth lake or a sun-soaked Mediterranean bay with a limited amount of time behind the wheel and an anxious PR representative watching our every move, but here in the Solent, on a blustery autumn day with just the UK and Caribbean’s new dealer James Hart to help us get the best out of it.
Backed by wealthy entrepreneur Dr Karen Dickens, who owns two Comittis (this Breva 35 in the UK and a Venezia 34 in the Caribbean), their aim is to grow awareness and sales of what they both believe to be one of Italy’s best kept secrets. They have a point.
It’s hard not to fall for the Breva’s intoxicating mix of elegant proportions and classic design cues enhanced by the occasional modern twist. It’s what Riva did so well with the Aquariva and Comitti has pulled it off with this boat too.
There is something about an elegantly flared bow, tumblehome stern and reverse sheer transom that tugs at the heartstrings, especially when they’re set off by a lustrous metallic dark blue paint job and lashings of honey-coloured teak (varnished mahogany is an option).
Modern details like the angular kink at the aft end of the stainless steel windscreen frame, the double arrowhead mouldings in the foredeck and the bespoke Comitti-branded cleats add an unexpected twist and prevent it from being too much of a retro pastiche.
Close-up one or two elements, like the fit of the cockpit upholstery and the underside of the bimini cover moulding, don’t look quite as neat as you’d expect but perhaps that’s inevitable on a hand-made product where every boat is built to order, often with new adaptations to suit each customer’s demands.
Read our full review of the Comitti Breva 35 in the February 2021 issue of Motor Boat & Yachting, out February 7.
Italian start-up Sealence is promising dramatic gains in the speed and range of electric boats thanks to a radical new pod-shaped waterjet, reports Hugo Andreae
DeepSpeed’s electric waterjets could be the key to unlocking more speed and range from battery-powered craft
Building an electric boat isn’t difficult but creating one with the speed and range to rival a petrol or diesel powered one is a whole lot harder. That is the quandary that set Italian engineer William Gobbo on the path to developing a completely new kind of electric propulsion system.
Rather than simply swapping a boat’s combustion engine for an electric motor and leaving the rest of the drivetrain untouched, Gobbo realised that a holistic approach, which played to an electric motor’s strengths, would reap far bigger rewards. The solution he came up with is an electric waterjet that combines both the motor and the propulsion system in a single unit.
Lines show claimed efficiency of DeepSpeed jet vs props and conventional waterjets
This can be mounted under the boat IPS-style or on the transom like a sterndrive leg, and steers by vectoring its thrust IPS-style. The pod version can even be swivelled through 360° to provide reverse or sideways thrust.
Called DeepSpeed, this innovative new propulsion system offers a number of potential benefits over both propellers and conventional waterjets. Firstly, there are no associated mechanical losses as there are no gears, shafts or universal joints transferring power from the engine to the drive, just a pair of wires taking current from the batteries to the motor.
Secondly, it’s a much smaller, lighter package that weighs a mere 75kg (ex battery pack) compared to around 660kg for a Volvo Penta D4 and takes up far less space than an engine and fuel tank. Thirdly, unlike a propeller that becomes less efficient the faster you go due to cavitation and tip losses, a waterjet actually becomes more efficient.
Lastly, the shape and position of the DeepSpeed pod puts it directly in the path of water flowing under the boat rather than having to redirect the flow up through an intake system and out of the transom as you would with an inboard waterjet. This reduces complexity and inefficiencies. The result, according to Sealence, is a drive system that is more efficient than either a propeller or a waterjet through the entire rev range, even at low speeds where waterjets usually struggle.
Gobbo first proposed the idea back in 2007, using computer simulations to test its potential, before developing the first working prototype in 2010. However, it wasn’t until the arrival of Professor Ernesto Benini, an expert in fluid dynamics from the University of Padua, that its full potential started to be realised in 2016.
The team behind the project now comprises 21 different specialists including engineers, designers, hydrodynamicists and even a powerboat racer, who together form the parent company Sealence.
It’s no coincidence that the latest DeepSpeed prototype resembles the jet housing of an aeroplane engine as, like a turbofan, it is designed to funnel water (rather than air) in the front end and accelerate it out through a smaller nozzle at the back. However, instead of a central hub-mounted fan compressing it and combining it with burning fuel, the DeepSpeed jet uses impeller blades on a hubless revolving outer ring turned by a powerful electric motor.
Hubless rotating impeller blades generate thrust
The faster the boat goes, the more water is force fed into the jet, increasing its overall efficiency. Other associated benefits include a reduction in noise and vibration due to the motor being located outside the hull rather than inside it, and the absence of any additional cooling system.
Currently Sealence is working on two DeepSpeed models, the 120e and the 280e. The former is continuously rated at 72hp with a peak power output of 92hp but due to the added efficiency of the jet’s design it is being touted as the equivalent of a 120hp combustion engine.
The latter is rated at 163hp with a peak of 244hp but is claimed to be equivalent to a 280hp combustion engine. Both can be fitted as single or twin installations in either sterndrive or pod-style mounts. According to Sealence, when fitted to a 40ft 12-tonne sportscruiser, a pair of 280e pods would give a claimed top speed of 38 knots.
The integrated system combines the jets with batteries, generator, fuel and solar cells
A number of boat manufacturers including Amer Yachts and Scanner RIBs are already looking at incorporating DeepSpeed jets into new or existing boat designs, two of which were exhibited at the recent Genoa boat show.
The future
Sealence’s longer-term goal is to offer a complete hybrid electric drivetrain package that includes a modular system of expandable lithium ion batteries, solar panels, a diesel range-extender and a range of different DeepSpeed jets up to 540hp all controlled by a single Smartbox. This will enable it to power a wide range of different craft from 9m to 24m.
“The aim is to drastically cut energy consumption but still increase navigation speed without noise emissions and avoiding the pollution of both water and air,” says Gobbo.
If it can deliver on that promise and demonstrate to the world that the DeepSpeed waterjet does live up to these ambitious claims, it really could be the start of an electric revolution.
First published in the January 2021 issue of Motor Boat & Yachting.
Volvo’s latest Assisted Docking software claims to take the stress out of berthing by automatically compensating for the effects of wind and tide.
Forget personal shopping assistants, the latest trend in the world of boating technology is personal docking assistance.
And while it’s only a matter of time before fully automated hands-free berthing becomes a reality – Volvo demonstrated a working prototype back in 2018 which relied on radio beacons installed around the berth – we’re not there yet.
In the meantime, both Volvo and Raymarine are locked in a battle to get as close to that as possible without taking control out of the hands of the skipper.
Last year Raymarine launched its DockSense system using a network of cameras around the boat to set up a virtual bumper that stops it bumping into anything as it comes into a berth. Now Volvo has hit back with a new development of its own.
Launched last month at the Consumer Electronics Show and available to the public this spring on both new and existing IPS boats, Assisted Docking claims to take the stress out of berthing by automatically compensating for the effects of wind and tide.
This may not sound like a big deal but in reality this is the one aspect of berthing that many boat owners still struggle with.
Even with the latest joystick-controlled boats, skippers have to second-guess how the wind and tide will push the boat around as they try to squeeze into a berth.
With Assisted Docking, all that is taken care of, meaning the boat now goes exactly where you ask it to.
Read our full report on the Volvo Penta Assisted Docking system in the March issue of MBY, which is out now.
Mercury has launched its most powerful outboard engine ever, a 600hp 7.6-litre V12 with a host of radical new innovations. We reveal its innermost secrets
For the last few years Mercury and Yamaha have been slugging it out for the title of the world’s most powerful production outboard engine, creeping up in stages from 400hp to 425hp and finally 450hp.
Now Mercury has knocked Yamaha clean out of the ring with a punch so big it’s hard to see anyone bothering to challenge them. The US engine builder’s latest launch is a monster 7.6-litre V12 outboard engine delivering a staggering 600hp and easily taking the title of world’s most powerful outboard engine curently in production.
The new Mercury monster 7.6-litre V12
To 50-something year-old sportsboat owners brought up on a diet of spluttering two-stroke oil-burners struggling to make more than 60hp, it seems an utterly outlandish proposition and yet Mercury is fully expecting to sell thousands of them, mostly as twins, triple or even quad installations. The world, it seems, cannot get enough of big outboard-engined day boats and cruisers – and it’s not just the US builders – everyone from Windy to Wally is building them. So what are the secrets behind Mercury’s new
600hp V12 and how has it managed to outsmart the opposition.
How do you create the world’s the most powerful production outboard?
The starting point for building the most powerful outboard engine in production, is an all-new narrow angle V12 block with the same 60 degree angle between its banks as the smaller V8 and V6 ranges. Naturally aspirated with quad cams, 4-valves per cylinder and indirect injection, the emphasis is on smoothness and refinement as much as maximum power. As well as the inherent natural balance of a V12 configuration, every effort has been made to reduce unwanted noise and vibrations.
A key part of that is a revolutionary new design that means the whole top section of the motor remains fixed at 90 degrees to the transom with only the slim swivelling lower gear case taking care of steering. This has a number of advantages; first, there is no need for any external steering rams, it’s all taken care of internally with only a digital fly-by-wire link to the helm.
The relatively narrow gearcase can swivel through 45 degrees
Second, the relatively narrow gearcase can swivel through 45 degrees compared to the 30 degrees which most outboards are restricted to. This makes for better manoeuvrability, especially at slow speeds where the joystick can make full use of the steering angles to vector the thrust in opposite directions when moving the boat sideways.
Third, with no need to leave big clearances between the engines you can fit more of them onto the same transom or leave the extra room free for bigger swim platforms. Fourth, the engineers and designers only have to worry about the engine’s drag through the air and water in one fixed position rather than when angled off to the side. And last but not least it enables a more rigid mounting position for greater smoothness and refinement.
By keeping the pivot position quite low and some distance from the transom this doesn’t compromise its ability to tilt, it can still lift the propeller clear of the water and its intrusion into the boat is barely any longer than the V8’s.
Two-speed gearbox
The other big innovation is a two-speed automatic gearbox (first gear is around 20% lower than second) which enables better acceleration onto the plane, even on big heavy boats, without compromising quiet, fuel-efficient high speed cruising. This is all taken care of by the engine control management system based on throttle and engine speed and is said to be so smooth that you’d be hard pressed to notice it shifting. Helping this is a hydraulic wet clutch design that allows a degree of slip for super slick movements in and out of gear and synchronised gear shifting for multiple installations that ensures all the engines change gear at exactly the same time.
Putting all this power into the water is a counter-rotating twin propeller set up designed for maximum bite on the water rather than all out speed. Mercury says despite the V12 being produced as the most powerful production outboard in the world, it has been optimised for maximum speeds of up to 80mph (70 knots) so it’s no slouch but nor is it aimed at the 100mph plus brigade that its single-prop Mercury Racing products appeal to.
That’s because the main market for the V12 is likely to be large, luxurious sportscruisers of 40ft or more rather than smaller, more focussed performance boats where power to weight is key. The V12 weighs a formidable 544kg giving it a power to weight ratio of 1.1hp per kg whereas the smaller, lighter 450hp supercharged V8 has 1.44hp per kg. The reason they are expecting the V12 to sell so well on these larger craft is not just the extra speed and refinement of a V12 petrol engine compared to a noisier inboard diesel but because of the room it frees us on board. The engineroom on a 50ft cruiser typically occupies a third of the boat’s overall length, valuable full beam space at the back of the boat that could be used for extra accommodation instead.
Fuel for thought
No figures for peak torque or fuel burn have yet been released but Mercury is confident that owners will be pleasantly surprised by both. The V12 is a deliberately under stressed engine with maximum power delivered anywhere from 5600-6400rpm depending on propeller and boat set-up. So confident is Mercury in its reliability that minor service intervals are every 200 hours (double that of its smaller siblings) and thanks to a new top opening access hatch these can be carried out with the boat still in the
water.
Major service intervals requiring a lift out are every 1,000 hours or five years. Low internal friction combined with the latest lean burn technology and that two speed gearbox means the engine rarely has to work hard once the boat is on the plane. The icing on the cake is a brand new digital throttle with an integrated digital display for key engine data and push button access to new features like active trim control.
Pricing for the V12 has not yet been announced but early indications are that it will be around 10-15% more than the price of two 300hp V8s, suggesting a price of more than £50,000 in the UK. However, with the expected savings in fuel and reduced drag of a single big V12 over twin V8s and the prestige of having the world’s most p[owerful production outboard on the back of your boat, even that isn’t likely to be an issue.
The first V12s are due in Europe this summer and we promise to bring you a full sea trial as soon as travel restrictions allow.
