Thank you so much for all your recommendations. We just returned from Grand Cayman. Did not get a chance to do Turtle Reef but will certainly do it next time. The deep dives were not a problem at all; actually after diving in Cayman I feel like I am an improved and more confident diver. I reached out to DNS, but they wanted to schedule our dives in advance and I just didnt have a firm schedule in mind before we left. We ended up going with Nick at Deep Blue Divers and had a fantastic experience. I would recommend Deep Blue and would dive with them again. We did three days of diving of the North wall and all the sites that NC DeepDiver recommended. Will save Kittiwake for next time. It cost us $90 for the two tank AM dive.