There were barnacles and other growth of course. But, most of the bottom was covered with thousands of nice sized mussels:
Somewhere in the above photo is a mussel covered sail drive. Below is another view:
I was severely tempted to gather a pound or two of the mussels and whip up some Mussels Posillipo for dinner.
But, I instead left them all for the Seagulls who with several hundred pounds of mussels piled up next to the dock will have thought they had died and went to heaven.