I took a cavern class at Gennie last Feb. It was a good class, second only to my rescue class. If you have never dove Gennie, the current comming out of some of those caves is a lot more than you might expect. I have heard it described as swimming up a fire hose and that's about what it's like.
If you don't have a long hose on your second stage, consider getting one or at least borrow one for the class. It makes sharing air a lot easier. I borrowed one for my class and bought one, 6 ft, as soon as I got home for my normal diving. I find it a lot more comfortable that the standard 3 ft hose.
I also added 2 D rings to the lower tank band of my BC. One on each side of the tank, they are held in place with weight belt weight keepers. It allows me to clip my reel and a backup light back behind me and keeps them from dangeling. I also found I liked this addition to my gear and have kept it (and added it to my second BC as well).
Even if you don't intend to continue on to cave, the cavern class is well worth taking.