I have a 1999 Fisher Avenger 14SC aluminum boat. The rear deck of the boat needs new carpet. I saw that as a great place to add a hatch. When I removed the deck, I saw that the both sides were filled with a large blob of foam. It is dry and in good shape. Stupid question, does this need to be there? This boat is not going to sink without it. They are only about 15"x12"x 12". What would happen if I removed this and how about if I removed half? Thanks.