Yes...the south end has some old structures that have washed into th Gulf and now sport a nice collection of gorgonians and fish schools. I've seen lots of snapperr and even a 4' Barracuda down there. Water in early summer is usually very clear...and about 12-15 deep at the structures. The south end is also a vast bird sanctuary, talk about noise..amazing when you get thousands of birds together in one place. Its also cool to stop and watch them feeding in the tidal flows from the Bay into the Gulf. The north end drops to about 80-90' and has very fast currents along the ship channel, with excellent Tarpon fishing in summer. The east side has a good artificial reef about 500 yards off, made up of old construction debris..but full of snapper...Hmmm good eatin!
If you get a chance to get off the boat and onto the island, its a wonderfull walking history tour of old Florida, and the military base that was there. Lots of old brick streets and buildings, definatley worth the walk!