Key West is great in a lot of ways, but for lots of people, it's the coral reef that counts. If what you like is historical architecture and a quaint city and lots of places to eat out and drink at bars, then there are many more cheaper places in the world that will suit your needs. Key West has all this PLUS the reef, the Gulf and the backcountry.
The coral reef in front of Key West is part of North America's only living coral reef, and begins all the way up near Miami and continues out past Key West, to the Dry Tortugas. It's just around six miles to the reef from Key West harbor, making it a short drive. On calmer days, you can get out to the reef for snorkeling, spearfishing, fishing or scuba in a small boat. I've seen flats boats and skiffs make it to the reef on calm days when the ocean is almost as flat as a lake.
For the visitor, snorkeling is the best way to appreciate marine life around Key West. Most beginner snorkelers need very few skills, and snorkel companies in Key West will provide all the gear you need if you take a snorkel excursion while here on vacation. If you've ever gone swimming, then you're half way there. Snorkeling in the ocean on a calm day is easier than swimming in a lake because the salt water helps so much with bouyancy. Plus, you wear a life jacket when you go out on a snorkel trip.
The hardest thing about snorkeling is getting used to the mask and snorkel. If a mask isn't properly worn, it will leak and cause you great misery. If there's a hair under the seal, water can get in. If the mask is too big, you will have trouble making a seal. Best advice for beginner snorkelers is to make sure you get a good fit before jumping into the water. Smooth away all your hair from your face. Put the strap on tight enough so it doesn't slip all around your head. Breath in through your nose and see if the mask tightens around your face, making a seal. Make it secure and tight but no so tight your face hurts. If you're in the water all this is just about impossible and you'll have to get out to fix it.
