So am I. Gato (212) had an exposed one : circlular ring around edge of well, top of buoy and two round greeblie bits, very detailed. Others had a manhole cover over (and I can't uite tell, but I think the exposed buoy top style sat just over the well, just above the deck? Maybe wehn they hadded the manhole cover they lowered? Not sure.
Anyway, lucky me, I'm doing Grouper 214, so I figure she and Greenling (213) would be very close to 212, so exposed buoy...I THINK somone on this forum has done a beautiful job on one, could be misremembering...
I'm doing some research, and I might cast a few. Early days yet!
I'll let you know what I find.