[Airborne1986]

Each of the pictures depict what appears to be a mattress in/near the water. This makes me wonder if these pictures really depict the first wave coming in. It would seem more likely that the mattress is part of the debris from the first round. Then again, the boats seem to be in pretty good shape. Could these be fakes?

[dead]

That object looks like a concrete base that was underwater before the water went away.

I would guess that it anchored something like swimming rope lines or buoys for the resort that the people are staying at.

It is definitely not a mattress.