In CUTTHROATS, you are a skilled diver living on Hardscrabble Island, a small seaport past its prime. You will try to salvage a sunken treasure from one of four shipwrecks; if you are successful, you will be fabulously wealthy and enormously respected among old salts. Some characters in the story will help you; others will try to stop you any way they can. If you can think logically and keep your throat intact, the treasure can be yours.
One of the underrated of the infocom series. Solved this one without much trouble and deserves a relook.