chemosavi wrote:That's it. On one of FS's boards. They didn't like it because I put too much curve in the foil shape and at any speed it got whacky. Once you got past 15 or so knots it wouldn't stay in the water easily.
Chemosavi, correct me if I'm wrong, but for gear weighing between 150 and 250, going at speeds of 20 mph you will want approximately 20 square inches of area completely underwater and also you will want the edges to penetrate the water at approximately 45 degrees.
It looks to me that once that foil reaches speed, the only part in the water will be a small bit of the curve, and it will be almost completely flat. At a guess you have around 140 inches worth of foil there, when you should have 40. If you make your foil three times thinner won't that solve the problem of stability at high speeds?
The reason I'm asking is because I'm sure you've tried all kinds of things, and wonder what the results were.
I'm planning on building my own twin tip hydrofoils this summer myself.