Water Hazards, Key West
Due to all the hurricanes in 2005 most of the beaches have bacteria warning signs up. You'll notice the smell and brown look in the water. This is only for right along the coast though, once you get about 20 feet out you are good, so all boat/snorkling/sailing/diving/etc trips are all still very safe and beautiful.
My friend and I booked a snorkling trip out at the big reef. Unfortunetly, there were many jelly fish in the area (more than usual) and my friend was stung. The trip was suppose to be 2 hours at the reef but after all the jelly fish showed up everyone got back on the boat after only 30 minutes.
Not comforting, and the ocean is very grassy, which had me doing Daffy Ducks at all times, most embarrassing for Mike.
If you really must swim here, take the Adolph's Meat Tenderizer, I hear that takes the sting out on the way to the hospital. We only saw them on the Atlantic side, never on the Gulf side.