Seacraft 18 deck removal question

[erebus]

I had foam in the bilge on my 75 SF18.
It was only accessible after I cut out the rear fish box/bait well, which was also encased in foam.
After cutting out the box, the foam went all the way forward to the fuel tank coffin. Would definitely not be accessible without removing the fish box/bait well. Assumed it had to be factory.
Scraped it out with a trowel.