I came across some some horribly low-res old plans, in a language I don't understand, to build a radio-controlled boat that uses a gas airplane motor and propeller for propulsion. I don't have a gas motor either and have never built a boat, so naturally I couldn't get the project out of my head.
It has taken a lot of tweaking, but I think the boat is finally working well enough to share here.
I have taken the wonky old scanned plans and completely recreated them in 3D CAD. The plans I have attached are ready for laser-cutting or CNC-routing (from 3mm ply - the bounding box is 1200x600mm).
Parts List - Mechanical
1200x600x3mm Plywood (Marine grade would have been nicer, but I went cheap)
1mm Imbuia/Oak Veneer/Ply (or 2mm if you can get it)
3mm Balsa sheets
Glue (I used various, but waterproof and relatively quick-setting are beneficial)
Parts List - Propulsion
I would seriously do some of your own research, since my choices were based on what I could get cheaply/freely. I feel like this boat could perform a lot better with a better motor/battery/ESC combo.
2s 2800mAh LiPo
ESC (Mine was an unknown Amperage, make sure your's meets your motor's requirements)
Parts List - Steering
1mm Stainless Steel Cable
Bicycle Brake Cable Sheath
Parts List - Control
Radio Control Transmitter
Radio Control Receiver (I used a 5 channel, but only 2 or 3 are needed, depending whether you want to tilt the motor or not)
I found the original plans here. I tried to contact the site owner to see if he had ever seen one built, or knew where the plans came from, but so far have received no response.
I spent far more hours than I would like to admit on digitizing the old plans. I have never attempted a model with so many strange lofted curves, and Solidworks 2007's surface modelling is sketchy, if you'll excuse the pun. Rumour has it that the recent versions have some rather fancy tools for unfolding surfaces, but I don't have access to those. In the end I decided to model the whole boat as a solid, and then use a multitude pf planes and carefully shaped surfaces to cut it into profiles. The "sheet metal" tool was able to unbend one or two curved surfaces, but I anticipate skinning the whole boat with hand-cut 1mm ply, so I am not going to fight with it to do the trickier ones.