Plywood Offshore catamaran approx 18ft

[Tore_M]

I want to design my own boat in plywood, but there is a long way from just thinking to actually building. This is what I'm thinking about.

Where should I start ?

regards

Tore

[Chris Ostlind]

Start with a known, well behaved hull that has a known engine package that is within your budget and take some general reference measurements from the chosen example to get you started. It's going to be pretty difficut to replicate all the chines and strakes of that illustrated hull in plywood as a straight-up build, but you can come decently close by building the general, background form and then applying surface strakes as necessary.

You may wish to take your newly acquited measurements into an easy to manipulate program, such as Carlson's Hulls (freeware on the Web) and start roughing-in the base shapes. Hulls files are importable in Freeware, where you can get more accurate readings on the hydrostatics, etc.

Both of these programs can output very nice .dxf files, as well as offsets for the cutting of the plywood. The .dxf files can be taken to a CNC router location and you can get the hull panels cut precisely, if you like.

Anyway, that's the way that I would do it if it were my project.