Hydrofoil Yacht Flies 5-Feet Above the Water About 10 years ago, the Flyak turned heads when the kayak with hydrofoils first lifted out of the water and "flew" above the surface. Once the rider got up to 6 mph, the foils propelled the hull above the surface. I'm surprised that it took ten years, but Enata Marine has taken the technique and applied it to a luxury yacht. The Foiler is a hybrid diesel-electric yacht with a retractable hydrofoil system that lifts the yacht five feet above the water. According to New Atlas, the Foiler has two 320-hp BMW engines that power a pair of generators used by two electric torpedo engines that drive the boat. Which is important, because the Foiler needs to build up a little more speed before it can fly. The vessel has to reach 19 mph before the foils deploy, but once it is out of the water, it can reach up to 46 mph. The four hydrofoils make for a smoother ride as the yacht cruises through the chop.