Tank coffin + foam questions

[dcobbett]

Couple of questions for those that have done new decks or replaced the fuel tanks in their 70’s vintage SeaCrafts.
I removed the tank from my SeaCraft on 1/6/06, and the bottom of the containment area looked like this (see first photo).

On 1/13/06 it looked like this (second photo). It seems to have “dried out”, but there are still a few dark (wet?) spots, and the bottom of the foam still looks damp.

Is the moisture in the surface layer of glass, or under it, and what do I need to do to make sure the area is dry before I put a tank back in there and seal the area up? Also, it looks like the floor of the tank area is just glass; I don’t see a level piece of plywood; it looks like the space is bridge by layers of fabric and resin. Is that normal construction in these hulls?

Finally, the foam at the rear face of the tank area has 3” +/- dia shafts cast into the corners (see third photo). They run all the way back to the bilge at the rear of the hull. They have a smooth bore, but nothing in them. Are they “standard” for these hulls, what were they for, and should they be closed up? Also, looks like the foam under the decks at either end of the tank space has settled. Should I try and get new foam in there or leave the space for air circulation, etc.?