[13Echo70271]

jvitiel, Nice rig, very clean V, wish mine was as clean.
You can test the foam from inside the rod box opening with the box removed, if you don't see wet foam you can cut a core sample with a spade bit. Very carefully drill down into the foam from the rod box opening. If you find wet foam, tear it out. If not, seal the hole with new foam and/or sealant.

Maybe more important while you're in there, check to see that your rod holders drain to bilge or deck also. I don't see covers on them.

There is room in the aft port hatch for a battery. It can be placed without any cutting, by removing the bin inside the hatch and reaching down. Get a tray or box and fix to shelf you find inside. If there isn't a shelf you can glass a plywood shelf or use starboard. All install work can be done from above. Adding a hatch makes the work a bit easier, adds access and isn't too expensive, about $35 on ebay.
I'd move a battery there .

Good luck,
Tom