Thanks for the response! But yes that seems to be the route I've been seeing. Free draining, and allowing plenty of room under the foam so water can easily travel to the back.
I'm an experienced DIYer, I can weld, woodwork, plumb, etc, but novice boater this will be my first non-canoe/kayak. So I apologize if I use improper lingo/sound stupid ;)
I got some questions about proper Jon boat drainage. I'm looking at modifying a 1448 to have a subfloor with flotation...