This is a great dive but be careful! There are a lot of boats that come and go in this area especially on weekends. Have a dive flag, and your metal detector. Gosport Harbor has lots of things people have dropped ... This is a great dive but be careful! There are a lot of boats that come and go in this area especially on weekends. Have a dive flag, and your metal detector. Gosport Harbor has lots of things people have dropped off their boats. There are 2 moorings for the caretakers of the Samual Haley House. It's best to pull up an adjoining mooring. You'll drop 15 to 20 feet on to a sandy, clay bottom. There are lots of old lobster traps, mooring rocks, chain, UNH Biology experiments and various former human belongings. I found a 8 HP Yamaha outboard that had been down too long to salvage and several boat hooks that I still use. The bottom drops to 50+ feet if you head SSW towards Star Island. The temp drops several degrees too and there are lots of lobster in the clay and rock bottom. Everything comes out at night though!