WOW, thanks for all the innovative observations. I knew I came to the right place.
I checked it over before I snapped the picture. It was not sharp & looks like it never was. Too high for me to touch so I can't comment on the material. I think geometry is wrong for a bobstay. Can't imagine it as a mooring
eye. It would break thin ice but I see no boats (especially sail) once October passes. Marinas
have drop-dead dates here for haul-out & shut down the travel lifts --crews go home. Tributary lakes & marinas
freeze over totally so no way to get out. If you planned to bang logs I think you would just want them to roll off a hard plate.
I noticed the overhang of the upper where this is located so it looks deliberate & fitted.
Is this like tail fins on a classic car?