The marina we have our boat at is highly transient. And it's under renovation. Construction turned the thing over. But it's a nice big stone. Bigger than my wife's.

I asked the marina already if anything had been reported lost in the past but its under new ownership and they blew me off. It's a big tourist destination in Florida. I doubt any locals would keep their boat at this place. Finding the original owner of this ring I think would be futile.