Starting from Cancún Centro in the northwest, all of Isla Cancún’s beaches are on the left-hand side of the road. (The lagoon is on your right; don't swim in the lagoon because of crocodiles!) The first beaches are Playas Las Perlas, Juventud, Linda, Langosta, Tortugas and Caracol. With the exception of Playa Caracol, these are Cancún's most swimmable beaches.
When you round Punta Cancún the water gets rougher (though it's still swimmable) and the beaches become more scenic as white sands meet the turquoise-blue Caribbean, from Playa Gaviota Azul all the way down south to Punta Nizuc at Km 24. Playa Delfines, at Km 18, is about the only beach with a public parking lot big enough to be useful; unfortunately, its sand is coarser and darker than the exquisite, fine sand of the more northerly beaches.
Under Mexican law you have the right to walk and swim on every beach in the country except those within military compounds. In practice, it is difficult to approach many stretches of beach without walking through the lobby of a hotel, particularly in the Zona Hotelera. However, as long as you look like a tourist (this shouldn’t be hard, right?), you’ll usually be permitted to cross the lobby and proceed to the beach.
Avoid swimming along the shores of Laguna Nichupté. The lagoon is a crocodile habitat and, although attacks are rare, you're better off at the beach. In April 2015, a reportedly inebriated man ignored the many signposts warning that the lagoon was not safe for swimming and died in a crocodile attack.
Cancún’s ambulance services respond to as many as a dozen near-drownings per week. The most dangerous beaches with the strongest undercurrents line the eastern shore, from Playa Chac-Mool at Km 10 to Playa Delfines at Km 18.
Though the surf is usually gentle, undertow is a possibility, and sudden storms can blacken the sky and sweep in at any time without warning. A system of colored pennants warns beachgoers of any potential danger:
- Blue: Normal, safe conditions.
- Yellow: Use caution, changeable conditions.
- Red: Unsafe conditions; use a swimming pool instead.