My computer registered 73 degrees at depth yesterday (Feb 3rd) on the shark dive with Stuart Cove's. There was a slight thermocline at around 30 fsw, you even could see the shimmer as you got close to it, but it was mild, only a few degrees. We wore 3mm hooded vests under our 3mm full wetsuits and were very comfortable. Most wore just a 3mm full and were fine but we were doing eight dives in two days so the added insulation was worth it.
The shark feed was a blast. I can see how people could get bored with it if they've done it a couple of times where you just sit there watching. But if you've never done it before it's well worth it. Our DM/feeder got bit, which happens regularly, only this time penetrated the chainmail of his glove. He got a small cut on his thumb and one tooth punctured his thumb nail and lodged removing the tooth from the shark.
As much as some find the feeding thing bad for the natural behavior of the sharks I saw that it did serve a useful purpose. Some of the sharks had hooks in their mouths from fishermen and the feeder was able to cut the rigging free so that it couldn't get caught on anything. The hook that was left will rust out within a couple of weeks from there.
Have fun I'm sure you'll enjoy it. If you have any other questions feel free to PM me. I'm writing this as I wait for my ride to the airport so if you do PM me I won't see it until tomorrow.