South of Cancun and Xel-Ha, the snorkeling at Punta Cadenas is very popular. This shore-accessed snorkeling dive site is known for surges from November to April. The water depths range from surface down to 18 feet deep. The visibility can be up to 25 feet.
To reach the snorkeling in Punta Cadenas by air, you will need to fly into Cancun International Airport (Aeropuerto de Cancun - CUN). Some of the hotels provide shuttle vans or there are shuttle vans to be hired down to Punta Cadenas. Renting a car to drive around can be hazardous do to the potential for unwarranted police stops resulting in required immediate cash payments. An alternative airport option is to fly into Aeropuerto Internacional de Cozumel (CZM) and take the ferry from Cozumel to Playa del Carmen. From there, you can take a much shorter shuttle van down to Punta Cadenas.
Note: while snorkeling offshore here, keep in mind that from November through March you might encounter bull sharks right off the beach.
Overall, Punta Cadenas is the 35th most popular snorkel dive spot of all 40 snorkeling dives in Mexico.