floor question
 

i do have one question about the boat that maybe someone has some info on. the floor from roughly the tank back is floaty. i have checked the transom and stringers and there is no rot. but the floor doesnt touch the stringers but in a couple of spots. the floor is for a better word suspended, its like the fiberglass has broken away from the wood or something. does anybody else with a V-21 have this concern or seen it.
was this a common problem on these?
and what is the fix for it? thanks