The Equipment Needed to Snorkel
Some people choose to bring their own snorkel equipment. However, this isn't necessary. The snorkel equipment provided by a tour company is generally in good shape and has been cleaned thoroughly before being given to you.
Key West snorkeling tours can provide you with three pieces of equipment on your tour. The first is the mask. You can prepare your mask by making sure that it fits you correctly. See that it is tight enough to create a seal between your nose and the water, but don't have it be too tight that it cuts off your circulation.
The second piece of equipment that you need is a snorkel. Make sure that the snorkel attaches well to your mask and that it doesn't have any leaks or holes. You can check to be sure that the snorkel will be comfortable by putting the mask and snorkel on before you get in the water. Try breathing comfortably with the snorkel to prove that it works.
Some people choose to also use fins in order to propel themselves faster through the water. The tour guides can give these to you. Be sure that the fins fit well; they should be tight but not cut off your circulation. If you choose not to wear fins, you will need to bring along some study shoes that you can wear in the water. It is not a good idea to go snorkeling barefoot, since the corals on the bottom of the water can be very sharp and you will also harm them by stepping on them.