Where to find plans?

Small boats can operate in a certain range of conditions. As the sea gets rougher the ride will become more uncomfortable at speed until you are forced to slow down. Then a small boat that is designed to go fast will probably be less comfortable than one which is designed for slower speed operation.

You should start by looking closely at what boats are in operation in your area in similar conditions to those which you expect to use your boat.

In addition to the Kurt Hughes plan link I posted above, also contact Richard Woods. He has plans for an economical cruising catamaran which may or may not be appropriate for you. Either way it would be worthwhile to get his thoughts on what you need: http://power-catamaran-designs.com/

 

ok thanks. So I talked to a guy today that said a 24ft boat would work, but really no smaller. So I'll start in that range.

 

Have a look at Russel Brown's Skeeter. I don't think you will find a smoother ride at high speed.
http://www.biekerboats.com/Bieker_Boats/Skeeter.html