Fiberglass crabbing skiff

[Ranger]

I have it in mind to make a @15' fiberglass crabbing skiff, not that I need one - I just want to do it. The problem is that I have no real idea how. I am a good enough carpenter to make it out of wood, as the originals were/are, but I want to do it out of fiberglass. Having accomplished that, I would like to use it to make a female mold in order to duplicate the skiff. Again, I have no need to do that, either...

Anyway, I wonder about the advisability of using 1/2 " Styrofoam to craft the hull from, then lining it without and within with fiberglass and resin. I assume the boat would get its structural strength from the fg/resin. 1/How many layers inside/outside? 2/As long as I am working with foam anyway, can I go ahead and make the ribs, bow deck, seats, etc from foam and then fg it? (I would plan on a wooden transom).

I can't think of anything else I need at the moment (not knowing enough at this point to ask questions).

Thanks