Question generator, still seems to be working.
I will relay that to the person who is trying to find out what they are.
They will be pleased, no doubt.
It's a stone life ring.
Throw to a subject made to Walk The Plank, then throw them a stone life ring to make sure the job is done
You can see the remains of the cloth of a pirate shirt in photo 2.
Climate change has caused the sea levels to fall like in Lake Mead revealing evidence of this barbaric practice.
(Check the area closely for gold doubloons.)
I thought something similar on first glance.
Maybe there were chains attached to the iron straps for added effect?