Thinking About Taking On 50 ft Houseboat Build

Yeah, that's a molded build, with a 1" bottom and 3/4" topsides, so lots of veneers. A plywood version could have much of the topsides done in 2 layers of 3/8", but getting the bottom on, bending two layers of 1/2" will test your skill sets. Portions of that bow will surely need 3 layers of 1/4", probably the same for the forefoot.

 

Can I suggest that an easier boat to build will have the following characteristics:

- Outboard engine, saves having to line up shafts, stuffing boxes, etc. Just bolt it on the back and hook up some steering gear (although an inboard is not that much harder).
- Have developable surfaces so you can build the hull with plywood sheets rather than cold molding. Developable means that you can unroll it to a flat surface. eg: you can unroll a cylinder but you can't unroll a ball. It will be faster and cheaper than cold molding, and you can get a similar hull shape to the boat you mentioned.
- Buy plans that have full size patterns (like the one you mentioned) to save you from lofting, or better yet, get frames CNC (computer) cut to save time. (might not be practical depending on the size of your boat)
- Build something appropriate for what you want to do and where you want to do it. If you want something to go fishing for a few hours in calm water, the design above is probably good. I have no idea what you want it for, but if I were building a 30 footer, I would put an enclosed pilot house or a cabin on it for longer day trips and the occasional overnight... future girlfriends will appreciate this. I would also want something that can handle rough weather to go further offshore.
- Small enough to tow legally behind a car, without any special licence requirements. (check with your local licencing authority)

It's a bit smaller than your 31 footer but I think this design (or similar) would be a great one to consider, the "Chinook" in either 19' or 20.5'. http://www.boatdesigns.com/19-or-20-Chinook-pilothouse-sportfish-cruiser/products/793/