As an avid railroad and scuba fan, this was a fun find. And ironically it was right in front of my property! Three railroad wheels were sunk in 16 feet of water, and wrapped together with a galvanized cable. I know the previous owner was a big sailing fan, and I found pictures as well as the original mast from his sailboat in the rafters of our boathouse. It was common to moor a sailboat in open water rather than have it tied to a dock, so I assume that was the point of these wheels. He most likely had a rope that went up to the surface and had his sailboat tied off to it. It was common practice to swim or take a smaller vessel, such as a rowboat, to the sailboat and prepare it for sailing.