This small island is home to the world's second largest coral reef and is ringed by some 30 dive sites, mostly on the west coast. Obviously, the focus is on scuba and snorkelling, and the exceptionally clear warm water permits even novice divers and snorkellers a glimpse into the fascinating underwater world.
The island, some 50 by 15 miles, was the first point where Europeans stepped on Mexican soil. There are some small archeological sites on the island but most are quite difficult to reach. It's hard to get lost on Cozumel, as there is just one road that runs around the coast. If you plan on renting a moped, please exercise caution as traffic can be erratic.
You will want to visit Chankanaab Park, about 10 km south of the village. Here a lagoon teems with tropical fish in water so clear that they can be seen without even getting your feet wet. There's also a botanical garden, home to over 200 tropical plants from all over the world.
With over 80 dive shops you will be able to rent any equipment you might need. The beaches on the eastern side of the island are gorgeous but largely deserted as they are mainly unsafe for swimming due to the strong undertow. On the western side where the reef and best diving is, the beaches are mainly small and in many places the water's edge is rocky.
The small town of San Miguel has a wide range of eateries ranging from inexpensive to fine dining. Be sure to select your day to go to town carefully, several times a week, huge cruise liners dock at the International Pier three miles south, and tourists descend on the town for their obligatory two hours of shopping.
The general atmosphere is very casual in Cozumel, which has been described as a ski resort for divers. Only in the very best restaurants will you be expected to wear more than shorts and a tank top.