Definitely have to do the BH. Altho if you've seen one stalactite, you've pretty much seen them all. But, you're only talking about 15 minutes out of your day in the hole. I wouldn't waste time doing just the big hole itself more than once, but the exhilerating boat ride, beautiful scenery in the islands, the thrill of a couple of black tips up close and personal, plus the thrill of seeing my depth gauge just about pegged at 140' was worth the trip. Come to think of it, lunch on Half Moon, the booby nests and a couple of fantastic dives after the BH. Hell, maybe I will do it again.