Sorry saw this post a little late to be any help. We have done two snorkeling trips in the keys so far one in john pennekamp we where not real impressed
reef was pretty much dead didnt see a whole lot and weather was not great that day. Second was eastern dry rocks out of key west was alot better reef was in alot better shape, tons of fish and nice and clear water. Next I want to check out sombrero reef off of Marthon. I would be interested to hear about your trip and any good spots you found we love the keys and try to make a couple trips a year to the keys.