Cancun's greatest attractions are its stunning beaches, and  swimmers have a variety to choose from. Most hotel beaches are excellent, so try  several, particularly on the other end of the Hotel Zone from where you are staying. Beaches in Mexico are government property and therefore open to the public.

Beaches facing the open Caribbean Sea, on the long part of the L-shaped island, are usually wide and beautiful, but the strong undertow, abrupt drop-off, and pounding surf make it a challenge to swim. One nice public beach in this area is Playa Delfines. There are some stone benches for sitting and contemplating the sea, and showers, and there is no hotel (at least not  yet).

Beaches facing Bahia de Mujeres, on the short end of the L-shaped island, toward town, are smaller, shallow for some distance out, and  have little surf, making them great for swimming, snorkeling and other water sports. These beaches, including Playa Tortuga and Playa Caracol, tend to be  more crowded, as locals favor them as well. Another drawback here is that the  blue of the Caribbean is sometimes marred by dark seabeds of algae and other flora.