Jet boat build advice on ply thickness and fiberglass weight.

[Mrjake]

I've googled some info on deadrise. From what im seeing 10-18° of dead rise is optimal for jets. But you are right that it will pound in a chop. My plans are to use this mainly on small rivers that a prop would get chipped on and exploring small creeks and such.

 

[BlueBell]

Im hoping the driver weight being far forward on the boat will help with the porpoising.

As TANSL pointed out in an earlier post, you're solving problems that don't yet exist.
If you build to a proven design all this guess work goes out the window, but I suspect that would take all the fun out of your build.
Best of luck, be sure and post videos!

 

[Mrjake]

So I have landed on 3/8" ply for all parts of the plans. Sheated in 1708 and epoxy. For bow cover, windshield, dash, sole, and rear hatch cover i will use all 1/4 ply covered with 8 ounce fiberglass. Keel reinforced with a extra wide fillet with fumed silica and chopped strand fibers. 4lb buoyancy foam under sole and over the keel fillet. That ought to do it. Im also going to keep an eye out for a jet jump with trim to fit to 650cc yamaha engine to help in the event it porpoises. Thanks guys. And to calm any fears for those concerned I have 750k in life insurance to take care of the family if my boat turns into a surface to air missile or submarine.

 

[TANSL]

Enjoy it.
Good luck.

 

[skaraborgcraft]

I would love to see your build do you have a link? I hope to not hit an object at 40mph but i want to build as if I will at some point.

Yes. It was bitchered to be better with less HP rather than more. DK18 based build. A modified low Horsepower planing boat - The WoodenBoat Forum

 

[Mrjake]

Yes. It was bitchered to be better with less HP rather than more. DK18 based build. A modified low Horsepower planing boat - The WoodenBoat Forum

Thats a great boat! How many hours do you have in it? My 16ft spira build has me at 450 with some deck fairing and painting left to go.

 

[skaraborgcraft]

It was around 300hours if i recall. For a skinny boat, it was a good fish platform and it sailed better than it should. Another boat that I was made an offer I could not refuse on.

 

[Mrjake]

I wish I had went the stich and glue route on my first build. Would have came together much faster. I plan to sell my first build. I find i like buulding them more than I like using them!