I lived in Key West for about 6 months in 2005. Spent a lot of time on the beach hunting. That is where I got my first real taste for Metal detecting. Over the course of 6 months I found 2 gold rings, 2 silver rings, about $56.00 in change and of course a lot of trash. Most of what I found was in the dry/wet sand, not in the water. (I was not experienced in water hunting at the time) I found stuff on almost every beach where people swim (mostly Higgs Beach), but you can tell from what I found over a 6 month period, it was not like picking cherries from a tree. The island is coral and has almost no natural sand, it is all brought in from off shore, so depending on how much sand they have put onto the beaches for the tourists, there may be few or no targets. It is worth a try. You need to check with your cruise line to make sure you can bring your metal detector on board. The last NCL cruise I took, they did not allow you to take your detector on board. I will say that if I were going back to Key West for a visit, I would want to detect one of the beaches. Good luck and happy hunting. Ralph
