My Mini-Hydroptere Foiling Trimaran

Maybe you've heard of L'Hydroptere, a French foiling trimaran sailboat that's gone 56 knots (64 mph). The most recent 74 ft. long version evolved from a series of prototypes dating back to 1976. I like this boat. Like many sailing enthusiasts, I want to foil too. There are foiling sailboats that you can buy like the Hobie Trifoiler and the Windrider Rave, and there's a thriving class of tiny foiling boats called Moths. I live on a bay that can be a shallow much of the time. Besides the Moth being a challenging, crash-prone, wet boat boat to sail, its long t-foils wouldn't work well in shallow water. Trifoilers and Raves aren't made anymore, and I simply want to build my own boat. So, I'm modeling mine after the second Hydroptere prototype, which is about the same size as beach cat.

The Hydroptere uses surface piercing foils for most of its lift. There is a t-foil at the rudder, but the main foils at the ends of the cross beam (aka) are angled down at 45 degrees. As such, no sensors or controls are needed to change the foil angle to handle swells. It should ride up and down swells, and the faster the boat goes, the more it rises out of the water. Moving parts for controlling t-foils are complicated to design and fabricate and can be fragile, so I like the surface piercing foils. Note that there are many modern high performance foiling boats seen most recently in the America's Cup race, and the newer AC45 catamarans. The Hydroptere is unique though in its seaworthiness. It sailed from Los Angeles to Hawaii.

Here's a visual evolution of the Hydroptere:

I won't attempt a complete history of the Hydroptere here, but see this page for a gallery of pictures of the prototypes and of the latest boat. Click here to learn more about l'Hydroptere. One thing worth watching is this video, Hydroptere - The epic in 7 minutes. To jump to video of the first prototype click here. And click here to jump to video of the second prototype. Anyway, see the links below to see what's going on with building this boat.