I've always heard that the design of the boat makes a huge difference in that if your bow breaks a wave, you want it to break/drain out. Also, You'll want trim or trim tabs so that you can adjust how the boat is riding into the waves.

I bought a 20 ft based on several recommendations from dealers and friends. If Puget Sound is still, you can take anything out there. In parts of PS, 20 ft isn't big enough if it is rough, but I don't plan to be out there.

Waves will break into my windshield and it has a self draining bow. And I have trim tabs even though it is a jet sled. I got them because it is an inboard jet. I'm more comfortable with a safety margin.

So, it all depends on what conditions you are going to be out in, and how much room for error you want.

I don't know if this helps, but my 2 cents.