Audi dunks its e-tron program in the water with jet-powered hydrofoil board
The Waydoo Flyer might have been the cheapest electric foil board on show at this year's CES, but it wasn't the most advanced. A second e-foil came from a rather unexpected source: Audi. The company's e-tron program has made a move off land, spawning a vehicle that floats riders through air as it zips across water at speeds up to 27 mph (43 km/h). This is a very different kind of Audi EV.
Our first thought as we stared at the safety-orange and black e-foil board on display in Audi's CES booth last month was that it was a simple collaboration piece, a special-edition Audi wardrobe dripped over something like the Lift eFoil. But after digging a little deeper, we realized it's actually much more — an Audi-developed electric hydrofoil that appears smarter and more cleanly designed than the competition on or near the market.
As Audi tells it, the story of how an Audi electric foil board became an actual thing has its roots in the pastime of Franz Hofmann, an engineer whose day job involves work on Audi's hydrogen tanks. Outside the office, Hofmann viewed foils as a way of cranking his kitesurfing hobby up a notch, and turned to friend and aerospace engineer Christian Rössler for help. In 2015, the duo developed a unique hydrofoil, and Hofmann put it to good use traveling the world with his kiteboard.
Feeling that the foil design was destined for greater things than just windy weekend warring, Hofmann presented the design to Audi, which immediately saw its potential for taking personal electric mobility past the shoreline. Like other automakers (er ... "mobility companies"), Audi has some experience experimenting with lighter urban electric vehicles like e-bikes and electric skateboards, and the opportunity to marry efficient hydrofoil design with zero-emissions propulsion was too good to pass up.
Audi backed the project and eventually developed a prototype that looks immediately sleeker and more high-tech than other e-foil boards out there. At the end of a 39-in (100-cm) mast, the foil assembly includes an integrated 6-kW jet propulsion drive that Audi says is both efficient and safer than the simpler propeller drives featured on other foil boards. Audi's system uses an enclosed impeller to accelerate water and a downstream stator to eliminate swirl and keep that water firing in a straight line.
The rider controls the silent electric drive via a handheld remote, and the foil lifts the board out of the water at around 11 mph (17 km/h). The board can cruise at an average speed of 19 mph (31 km/h) or accelerate all-out to a top speed of 27 mph (43 km/h). The board-integrated battery pack keeps the jet drive firing for up to 18 miles (29 km), roughly an hour of on-water playtime.
The jet drive assembly is made out of aluminum to capitalize on natural water cooling, while the foil, mast and board are all made out of carbon fiber to keep weight down and stiffness up. The board itself weighs 40 lb (18 kg), before dropping the battery pack in.
With Hofmann still taking lead, Audi has developed and tested several prototypes of what it unofficially calls the "e-tron e-foil." It hopes to produce a limited number of boards later in 2019 and begin offering test drives to potential buyers.
Pricing remains anyone's guess, but nothing about Audi's design suggests an affordable, high-volume product. The company says only that current electric hydrofoil pricing is in the five-figure range, and it sounds like it has no intention of dropping below that level.