Small pontoon design qeustion

[Tysonsmith]

I have been looking at some small pontoons (14-16ft) for fishing but I would really like to build my own. I was considering buying the pontoons and going from there but there is a guy near me who is giving away some catamaran hulls from 14-16ft sailboats. Would this be a good substitue for aluminum pontoons? I would think that if the bouyance is comparable to regular pontoon than these cat hull would be even better due to the "fast" design. Comments??? Has anyone done this?

P.S. I will be putting a 25hp on this. And it will have up to 4 adults on it.

[Trevlyns]

Hi and welcome!

My guess is that the cat hulls would not be adequate for your purpose. A 14 - 16ft beach cat would normally transport two people without the added weight of a 25hp motor.

Best!

[Tysonsmith]

Originally Posted by Trevlyns

Hi and welcome!

My guess is that the cat hulls would not be adequate for your purpose. A 14 - 16ft beach cat would normally transport two people without the added weight of a 25hp motor.

Best!

That is what I figured. What if I were to make it a tritoon or quadtoon(if this would work) for that mattter? Would I still lack stability? The only reason that this is such a big consideration is because the hulls are free. How would I find out there bouyance rating?

[kengrome]

What if I were to make it a tritoon or quadtoon (if this would work) for that mattter? Would I still lack stability?

Here's what I think:

1- The engine is WAY too big for a boat with those hulls
2- There's not enough flotation in 2 hulls for 4 people

The only reason that this is such a big consideration is because the hulls are free.

There's nothing wrong with your idea of using 4 hulls to float 4 people, but you'll still have an engine that's way too big. Five horsepower will push a boat like this faster than you should be going -- which in my opinion is 8-10 mph max. Those are displacement hulls not planing hulls, so excess power will only waste money on fuel and possibly endanger you and your passengers.

You could go fast more safely if you use two hulls in front and two in back. Construction will be more difficult and time comsuming this way, but the boat itself will be longer so it will handle higher speeds a bit more safely. It won't have any reserve buoyancy forward though, so you'll see how easily it buries its bows the first time you run it too fast in some decent sized waves ...

But if you lay off the throttle and potter around at relatively slow speeds a boat like this might be ideal for a fishing party of four. It would certainly be cheap if you get the hulls for free ...

[Lei Kong]

are you interested in this one?

[Tysonsmith]

That looks like it would have more bouyance than the hulls I am looking at. You could say I would be interested. Why do you ask?

[Lei Kong]

we put 21hp inboard engine on this boat, this is the hull of my first boat, interior is under building now...