JEM Watercraft

Hi Matt, can you tell me what the theoretical maximum speed for the Sabalo is? I know various design software can give the theoretical maximum speed for a displacement hull. I just want a bit of an estimate to know how much sail I can put on.

If you're assuming energy input is constant to maintain the speed, the the max is about 5.5 knots. After that, you start needing a lot more energy to get it to go a little faster.

Thanks. As I will be sailing mine it is useful to know how much sail to put on to be able to achieve maximum practical speed without increasing the pressures unnecessarily. Cheers.

Sorry Matt, forgot to ask one more important question. Displacement? I know it will vary with load but max and min would be good to know.

Is it the same as the weight? From what I understand the maximum speed is a calculation based on motive energy minus resistance. I imagine keel length and the design of the hull (streamlining) would be the main factors. Am I right?

Displacement is the weight the boat can hold at a given waterline. Max speed has many factors. Hull/waterline length is one of the main ones.

Goany's next question is probly gonna be. "Matt, do you have any designs in the pipeline for a wooden jetski"?
Cheers John.

Svensons has something like that for an outboard. But that's all kinds of crazy.

john the pom wrote:Goany's next question is probly gonna be. "Matt, do you have any designs in the pipeline for a wooden jetski"?
Cheers John.

Hahaha. Not quite John. It's just that I would like to put enough sail on to be able to get somewhere near her top speed potential without overdoing it and putting too much stress on the boat. I am aware that it's a kayak, not a sailboat, but I think that the sailing potential is still quite good with the rig I have.

I think with all the formulas in the world there's still alot of guesswork in sail area calculations. And then there's the question of the best sail design, and I'm not going there.

Yeah I know I'm waiting on some results of your wing sail

john the pom wrote:Yeah I know I'm waiting on some results of your wing sail

Are you using a winged-keel