Marine

World's longest-range electric hydrofoil packs 120-kWh of battery

World's longest-range electric hydrofoil packs 120-kWh of battery
This otherwise nice looking machine is currently called the SpiritBARTech35EF
This otherwise nice looking machine is currently called the SpiritBARTech35EF
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This otherwise nice looking machine is currently called the SpiritBARTech35EF
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This otherwise nice looking machine is currently called the SpiritBARTech35EF
Lifting the hull out of the water reduces drag by as much as 75%, greatly extending range
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Lifting the hull out of the water reduces drag by as much as 75%, greatly extending range
At 100 nautical miles, the SpiritBARTech35EF is the longest-range electric boat of its kind
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At 100 nautical miles, the SpiritBARTech35EF is the longest-range electric boat of its kind
You certainly don't want to run into anything under the surface at speed
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You certainly don't want to run into anything under the surface at speed
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If you want an electric boat to get very far, you either need huge amounts of battery, or you need to lift your hull out of the water on a hydrofoil system to cut down energy-sapping drag. The SpiritBARTech35EF does both, for record-smashing range.

When Candela announced its "Powered by Polestar" edition C-8 back in January, its low-drag hydrofoil cruise and 69-kWh battery gave it a claimed range of 57 nautical miles (66 miles/106 km), vastly more than most standard-hull electric boats can handle.

Now, Spirit Yachts and BAR Technologies have teamed up to blow that figure out of the water, if you'll permit a largely unsuccessful attempt at hydrofoil humor. The catchily-named SpiritBARTech35EF – and I'm cut 'n' pasting that slop of alphanumerical diarrhoea, because I refuse to type it – carries no less than 120 kWh in its custom battery pack, and as a result, it can travel a full 100 nautical miles (115 miles/185 km), at a fairly decent cruise speed of 22 knots (25 mph/41 km/h).

Lifting the hull out of the water reduces drag by as much as 75%, greatly extending range
Lifting the hull out of the water reduces drag by as much as 75%, greatly extending range

This number clearly being larger than 57, we have a new electric range champion. To put this 35-footer's range in context, the average small pleasure boat burns a gallon of fuel every 4-5 miles, so 100 nautical miles represents somewhere around 26 gallons (100 L) of fuel. Most gasoline boats have tanks much larger than 26 gallons, but on the other hand, it'd be fairly rare for most of these boats to do 115 miles in a single day.

The SpiritBARTech35EF runs a single motor – an HPM-400 tailored to the job by UK company Equipmake, which builds some of the world's most power-dense and innovative electric motors. This motor, Equipmake's first foray into the marine sector, makes a fairly meagre 80 kW (107 hp), but that's enough to get the boat flying over the waves on its foils, and up to a top speed of 28 knots (32 mph/52 km/h).

We're seeing more and more hydrofoiling boats popping up in the last few years, if you'll excuse a second, slightly more successful attempt at hydrofoil humor. We expect this trend to continue, since pushing a hull through water drains so much energy that this sector will be extremely hard to decarbonize without finding ways to rise above the waves.

Source: Equipmake

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3 comments
3 comments
Nobody
The biggest problem with hydrofoils will be the trash in the water, weeds and shallow water. I can't think of anywhere I have boated in the past 60 years that would be suitable for hydrofoils except deep lakes. Rivers have logs, nets, old fishing line and old ropes. We had the motor ripped off our boat when a telephone pole suddenly bobbed to the surface in front of us while cruising down a major river. Lakes are also interesting. In my first 20 years of boating, I didn't have a depth finder. When I got one, I was shocked at how many shallow spots, tree stumps and rocks there were in the lakes that I boated. There is a reason that boat motors are built to tilt up if you hit an underwater object. Then there is the little matter of salt water and electricity not mixing well. I have seen enough boats sink to wonder what the high voltage hazard would be when an electric boat goes down or even get fully bathed in salt spray from big waves.
Daveb
SpiritBARTech35EF McBoatface would have more of a ring to it. And yes I also copy pasted.
jerryd
Such boats have serious problems and why they are no longer around from the 80s when they were popular. But cost of foil repair, trash on or breaking the foil caused it to die until everyone forgot.
The USN Pegasus 137' missile patrol boat hit a whale sending the whole crew to the hospital, the ship, the other 5 to the breakers and the whale didn't do well either.
Now for fun where you don't mind getting faceplanted like a surfboard version it's cool, but anyone onboard needs to wear a seatbelt or get smashed face first into the dashboard, windshield, etc.