Marine

Candela celebrates the first flight of its C-8 electric hydrofoil boat

Candela celebrates the first f...
Candela has already sold more than 100 C-8s, with production set to begin soon
Candela has already sold more than 100 C-8s, with production set to begin soon
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Candela has already sold more than 100 C-8s, with production set to begin soon
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Candela has already sold more than 100 C-8s, with production set to begin soon
The C-8's hydrofoil system reduces drag by as much as 80 percent, vastly improving its electric range
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The C-8's hydrofoil system reduces drag by as much as 80 percent, vastly improving its electric range
The "flying boat" will certainly be an arresting sight
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The "flying boat" will certainly be an arresting sight
Below 16 knots, the C-8 operates like a regular boat, and can retract its foils in shallow water
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Below 16 knots, the C-8 operates like a regular boat, and can retract its foils in shallow water
A cruising range of 50 nautical miles at 20-knot cruising speeds
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A cruising range of 50 nautical miles at 20-knot cruising speeds
The C-8 offers an autopilot function that'll steer you to set compass points hands-free
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The C-8 offers an autopilot function that'll steer you to set compass points hands-free
View gallery - 6 images

Candela aims to smash electric boat range records with its C-8, using a hydrofoil system that eliminates as much as 80 percent of the drag you'd get from a conventional design. The first prototype C-8 has now flown, and Candela has released video.

The marine sector is going to be hard to electrify. It takes a lot of energy to push through water, as David Hasselhoff would attest, and lithium batteries carry a fairly depressing 2 percent of the energy content of an equivalent weight of gasoline. Thus, electric boats simply don't go very far at the moment.

Candela's solution is to get the hull right up out of the water on hydrofoils. Takeoff speed for the C-8 is 16 knots (18.4 mph, 29.6 km/h), upon which it rises up until nothing but three carbon struts are visible touching the water. Under the surface, the front two are joined by a wing-shaped foil, and the rear terminates in a torpedo-shaped "C-Pod" electric propulsion unit with wings extending out from the sides. These foils are retractable when the water gets shallow, to the point where you can lift the motor out of the water entirely.

The C-8's hydrofoil system reduces drag by as much as 80 percent, vastly improving its electric range
The C-8's hydrofoil system reduces drag by as much as 80 percent, vastly improving its electric range

The motor makes 45 or 50 kW (60/67 hp), which doesn't sound like a heap, but Candela says it'll propel this 1,605-kg (3,538-lb), 8.5-m (28-ft) boat through the water at speeds up to 30 knots (34.5 mph, 55.6 km/h) thanks to that extreme drag reduction. At a cruising speed of 20 knots (23 mph, 37 km/h), Candela expects this thing to cover more than 50 nautical miles (57.5 miles, 92.6 km) on a single charge of its relatively humble 44-kWh battery.

The company says that's "two-three times longer than conventional electric speedboats with 300 percent bigger batteries," although if Sarvo Marine ever gets its shiny aluminum Sarvo 37 built, it promises a whopping 100+ nautical miles from an equally whopping 350-kWh battery pack.

Candela pitches the C-8 as a day cruiser, and while it can't compete with similar-sized dinosaur burners for total fuel range, it does have a few benefits on the side. Total silence is one, as well as the ability to cruise without leaving much of a wake behind you. Autopilot is another; the fly-by-wire steering system will follow a set course for you hands-free. And the ride will be super smooth as the boat glides over choppy water.

Candela says it's already taken 100 orders on the C-8, "even outselling most other 28-foot ICE boats in the premium category." At a starting price of €290,000 (US$330,000), it's a fairly pricey toy – but then people will flip when they see this boat rising up on its stilts and silently cruising off into the sunset.

Check out the video of the first flights below.

Hydrofoiling electric boat Candela C-8's maiden flight

Source: Candela

View gallery - 6 images
5 comments
5 comments
nick101
This is great! And considering what fuel hogs most power boats are, it's a wonder more boats aren't hydrofoils.
riczero-b
What a beautiful machine. Wonder if they also considered compressed air bubbling through the hydrofoils ? I can't help envisaging a horribly expensive crunch if the foils hit debris though.
martinwinlow
Oh, dear!! Loz Blain: Batteries may only "contain 2% of the energy content of an equivalent weight of gasoline" but electric drive trains are some 3-4 times more efficient than Otto cycle fossil-fuel ones. So, the 2% (which is a bit out of date anyway such is the pace of battery development) is really more like 10%. Whilst still only a fraction of the specific energy of fossil fuel, it still makes great sense in certain marine applications even for non-hydrofoiling watercraft eg https://www.electrive.com/2021/03/02/worlds-largest-electric-ferry-yet-goes-into-service-in-norway/ (there are many others).
martinwinlow
"The motor makes 45 or 50 kW (60/67 hp), which doesn't sound like a heap..." I'm also guessing you are unaware that electric motors generally have their power output specified in terms of *continuous* power, whereas ICE ones are usually specified in terms of *peak* output...? Ie a 50kW electric motor may have a peak output significantly greater than 50kW but which it will not be able to maintain for more than a short time.
unclejoe
I wonder if this technology could be adapted to a pontoon boat.