fiberglass boat design idea

I could point you to a dozen threads in this forum that planned to do that

 

Skin on frame does not have to be bent and retain the shape freestanding. The stringers are bent and attached to the bow and stern plates, left and right side balancing each other. Those stringers have the full bending force in the for the life of the boat, except for a little creep.

The stringers have to support the paddlers weight against the water pushing up. If they are too flexible they will bend to where the bow and stern are pointing up in the sky and you will be sitting in a bathtub with little freeboard.
There was an "Instructables" which showed you how to build a canoe out of PVE pipe. It did just what I am talking about. Bent so much that the whole thing collapsed and the guy fell in the water. It didn't make it away from the dock.

 

I have built a rough skin of frame boat with a tarp and some old sticks. It didn't just float but made me the champion of the junk boat race in Lake Petenwell, Wisconsin.