OOOOOOOOOPS. Thanks for the info.
I figure that the area southeast of Treasure is probably like so many of the shoal areas... Pretty good pile of rocks, some of which could raise havoc with a lower unit or keel. And unlike my diving days when fishing was normally done from an anchored boat and you could find a couple of anchors every time you went diving, today they use electric troll motors, so you don't even find the anchors.
Seriously, thanks for your efforts to define the shoal area north of Treasure, and I hope that the water will be clear and warm for at least another month, and the bottom filled with treasures (not the island!!!!). hope to see you again soon.