hello all, pretty new to the forum, have made a few posts.. I bought a Rinker 192 captiva late last season.. just used several times, love the boat.. I’ve been tinkering with I all winter, the other day I noticed.. in the storage compartment under the rear seat there is a bulge in the liner.. some spots I step on It and It bends in or pops flat.. others I.T feels like something is underneath.. what can this be? Is this potentially rot or foam expanding? I’m young and brand new to boating didn’t know rot existed when I was looking for this but I know the boat was in excellent condition compared to most I looked at. Sorry if I’m not being articulate, early and I’m rushing for work and this was keeping me up at night.