1978 240 SRV SDB- Blocks of foam in bilge? For flotation? I just bought a 1978 240 SRV SDB boat from Arizona and noticed that it has these huge blocks of foam in the bilge right next to the engines. This is the second boat that I saw they were in there. All the other boats of the same style did not. Was this Sea Rays' attempt at adding flotation to the boat?