Christian Bohlin Builds Giant Duck-Shaped Boat. JetKayak PowerSki High Performance 1. Quadski. JetLev-Flyer Water Jet Pack Facts. HYDROFOIL -- The Amazing Boats of Kotaro Horiuchi. Video edited by Ray Vellinga. Power JetBoard In Playing Video 2. HYDROFOIL -- Incredible human-powered flight!! Ray Vellinga video.