@unknownuser said:
I can draw it in SU flat but I can not get the curve of the hull.
The first thing you need to do is to draw a series of cross-sections through the main hull and the pontoons (one of them). Maybe every foot or so.
Then, if you wish, I can advise you on how to transform them into a 3D model.
Or, you can peruse this thread and see if you can work it out yourself.
[Gully Foyle]