New electric hydrofoiling boat from Sweden
A new electric hydrofoiling boat is on display at the Goteborg Batmassen (Swedish for ‘Boat Show’) this week, along with other electric boat technologies from the country that demonstrate how quickly electric boats are being developed and launched. Sweden is a leader in this regard, hosting the first all-electric boat show in Stockholm last May.
The One.fly, from Sweden’s Mantaray Hydrofoil Craft, is a 5 metre/ 16 foot boat that seats 4, weighs 380 kg (840 lbs) empty and can fly above the water for 2 hours at 25 knots (46 kmh/28mph). There are now 2 electric hydrofoiling boats in the show as Mantaray joins Candela Speedboat.
The boat has been under development for years, and its roots actually go back to a quirky human-propelled hydrofoil called the ‘Trampofoil’ invented in 1996 (!) which may turn out to have been years ahead of its time. Here it is demonstrated in a 2010 YouTube video, and if you skip ahead to about the 1:00 mark you can see it in full action. It is not dissimilar to the two electric powered ‘watercycles’ we wrote about in January)
Alexander Sahlin is the inventor of the trampofoil, and while the initial concept may look amusing, at the core of it is the basis of the One.fly. The essence of it is the hydrofoiling extension at the bow of the machine.
New electric hydrofoiling boat history: 2012 – 2017
Before we get to the videos below, we should note that the technology and company have used different names during the evolution over the years, including ‘Foiltwister’ and Elektrofoil’
You can see in the Foiltwister technology animations video from 2012 a demonstration of how the single front appendage works. The next video is of the Foiltwister technology being put to use in real life action on a (gas powered) boat in 2013. This boat was actually demonstrated at Stockholm’s Allt för Sjön (Everything for the Lake) show in 2012. The third video shows the actual prototype of the One.fly (referred to as the EFP 16) in 2017.
The Mr. Sahlin’s Swedish patent describes its use and how it different from other hydrofoiling wings: “This results in a transversal movement of the hydrofoil craft relative to the water surface during forward travel. The hydrofoil arrangement also increases the roll- stability for a hydrofoil craft”. (btw, that’s Mr. Sahlin in the 2017 video)
2012
2013: Foiltwister
2017: EPF16 – One.fly prototype
2018
To bring the One.fly to its final design as being shown in Goteborg this week, Mantaray enlisted the talents of Mannerfelt Design. The company has an unmatched pedigree, having been founded by international sailor Ocke Mannerfelt in 1978 and proceeding to notch up 23 UIM (Internaional Powerboat Federation) World Titles for their work on watercraft of all shapes, sizes and propulsion. They speak about their work on One.fly in the video below.
There is no doubt that hydrofoiling is going to play an increasing role in the future of electric boats. The Candela Speedboat (also from Sweden) won a ‘Best of Boat’ Awards in 2019 and was nominated for the European Powerboat of the Year. Their website details the advantages of hydrofoiling and the massive reduction in drag and therefore increased range and speed for an electric motor when the boat’s hull is lifted out of the water on its foils. To quote their research: “Hydrofoils give a 50 % reduction in energy consumption“.
The main difference between the Candela and the One.fly is that Candela uses a proprietary software program to adjust the foils up to 100 times per second as the boat is travelling, whereas the Mantaray design uses the physical mechanics of the patented bow extension.
Hydrofoils play important part in the electric boat future
Another hydrofoiling boat making the news is SeaBubbles. which was designed as a ‘flying water taxi’ concept by Alain Thébault, the man who pioneered hydrofoiling on multihull sailboats. The authorities of Paris tested and monitored SeaBubbles on a route on the Seine last fall and it should (hopefully) be approved as an option for commuters this spring. In fact, Manta has the sketches of a similar pod-type boat on their site.
Then there are the large and small on either side. On the grand side, M. Thébault is also behind the FlyBus 32 person ferry, and designer Pierpaolo Lazzarini came out with a concept 10.5m/33ft luxury hydrofoilng yacht.
On the smaller side, see our look at 10 hydrofoiling electric surfboards (e-foils), the hydrofoiling jetski developed by the University of Western Australia Electro.Aero and there’s even the Deepseaker, a small submarine that hydrofoils when it is above water.
When looking at the history of the One.fly, it has to be noted that all of the testing was done using ICE/fossil fuel motors. It is available with fossil fuel propulsion but the news this week is that it is now also available with an electric outboard.
Presumably, it is only in the last couple of years that there have been sufficient numbers of electric motors with sufficient power to raise the One.fly onto its foils. It’s very exciting to see not only the patented and proven technology, but also that it is electric motors that help the whole idea fly.
