I'm guessing that with this weekend's forecast of highs of 71 degrees, and a 30% chance of rain, that going to the Dry Tortugas and snorkeling is a bad idea. Am I right? I'm thinking of doing a glass-bottom boat tour instead. What do you all think? I'm coming from the midwest, and 71 degrees sounds like heaven, but I don't have a clue how cold or warm the water is right now.