: It does seem fairly obvious that a strip hull has more rigidity than foam
: from the word go. We know the strip hull works so it seems logical that we
: will have to do something to bulk up the foam core hull to be as stiff and
: to be as capable of warding off penetration.
: As far as I can see you have but a few ways of doing that and all of them add
: up to more weight.
: To me the calculus is this. You are saving a little weight with the foam core
: but are giving up a lot of other engineering properties. If you don't get
: enough of that stuff back the boat may not have enough margin of safety
: for all-around use.

OK, I gotcha - I agree that most think of using foam to save weight, and that when you look for equal strength to wood, the weight saving evaporates. This is not my concern in using the foam. And it's not necessary to make a foam boat just as stiff and penetration resistant as wood - that may be a good benchmark, but maybe I can live with less of both qualities.

Making some engineering evaluations of the material is what I'm after, in addition to its favorable prototyping qualities. I'm looking at this project as a test bed for my design, as well as for using foam as a building material. I will probably be involving students in the project for independent study, so it's also a teaching exercise. I plan to document the whole thing, so I guess I should be finalizing my design instead of arguing about material selection. I assume that, as usual, the design will indicate fairly immediately if the materials are not up to the job by breaking in half and dumping me in the sound.

Carl