Swedish electric hydrofoil boat starting to fly!

With their third production electric hydrofoil boat completed and recent selection as one of Sweden’s hottest tech startups, Candela Speedboat is making waves everywhere except when its design flies above the water.

When Gustav Hasselskog founded Candela in 2014 with the intention of creating an electric boat matching the range and speed of a gas burner, he knew it would be challenging. So he put together a crack team of people with backgrounds in hydrodynamics (with 6 America’s Cup wins), flight control electronics, structural composite engineering and the software used for dynamic modelling.

A high speed e-boat needs to address some physics

The challenge faced by all e-boat designers is one of physics and current battery technologies. One kilogram of gasoline holds about 15 times the usable energy of the best battery packs, and obviously weight is not good for speed. Working to the benefit of the electric boat is that the electric motor itself is much more efficient at converting that energy into motion, but all boats have to face the physics facts that even a planing boat needs an awful lot of energy just to get through the water.

So a hydrofoil that raises the boat above the water gives a great advantage in terms of both energy efficiency and speed. On the other hand, something literally flying above the water is inherently less stable than something travelling in the water.

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A lot of things to contend with! But the team got to work and in late 2016 completed and tested a 7.5 metre prototype that achieved a range of 50 nautical miles per charge running at a speed of 25 knots – comparing favourably to ICE boats of similar size.

Here’s a video of a test run in April, 2017

After some improvements, tweaks and proof of the refinements, the company started production for customers in the autumn of 2018. At the time Hasselskog told Swedish tech site NYTeknik website “It feels exciting and a bit scary to be up and running! But we really believe in this technology and believe that it will hit properly as soon as we get our the boats out into the market.”

The big reveal of the electric hydrofoil boat was at Sweden’s first all-electric boat show in Stockholm May 11, where a full speedboat unexpectedly rising out of the water caused enough of a stir to be featured on Swedish national TV news.

Three of the SI model boats have now been completed with the goal of having delivery to 10 customers by the end of 2019. Here’s a great video of two of the first boats meeting each other on the water, and another of the Candela and a Wildtech electric hydrofoil on the water at the Stockholm show.

In addition to all of this progress, the company was also added last week to NYTeknik’s annual Sweden 33 List of the country’s most exciting tech startups. Others that have been similarly honoured in the past include Spotify and Minecraft.

This is not your traditional boat building

The achievement is a recognition that creating a flying watercraft like the Candela S1 is not your traditional ‘boat building’.

There is a patent-pending system that controls the height, roll and pitch of the hydrofoils, an innovation necessary because the flaps and ailerons that larger commercial hydrofoils use wouldn’t be robust enough for consumers.

A mechanism was designed to retract the foils into a step in the hull (front) and the swim platform (aft) for shallow waters and storage.

A flight controller captures the boat’s movements from 7 sensors and uses advanced sensor fusion algorithms to overcome the inherent instability of foils

Ultra-light hull materials are used, including a carbon fibre single skin in the hull, deck, hydrofoils and interiors. On their website Candela says that hull and deck together weigh about 250kg / 500lb and that a similarly sized fibreglass could weigh six times as much.

The website also has the full specs for the boat.

None of this comes cheap, of course. The price of a Candela S1 is £190,000 / US $210,000. But the cost doesn’t seem to be getting in the way of Gustav Hasselskog’s 2014 dreams. He says they already have about 150 advance orders.