Puerto Morelos [1]’s most spectacular attraction is snorkeling [2] on the reef. Directly in front of the village, around 500 meters (0.3 mile) offshore, the reef here takes on gargantuan dimensions—up to 30 meters (99 feet) wide.
Winding passages and large caverns alive with fish and sea flora make for great exploring. And since it’s a marine reserve and fishing and motor traffic are limited, the reef is more pristine here than almost any place along the Riviera.
A local cooperative (central plaza, Av. Rafaél Melgar s/n, no phone, 9 a.m.–3 p.m. Mon.–Sat., US$25 pp for 2 hours) offers guided tours of the reef, with boats leaving every 30 minutes—or sooner, if there are four snorkelers—from the municipal pier.
Links:
[1] http://www.moon.com/destinations/cancun-the-yucatan/cancun-cozumel-and-the-riviera-maya/the-riviera-maya/puerto-morelos
[2] http://www.moon.com/destinations/cancun-the-yucatan/cancun-cozumel-and-the-riviera-maya/the-riviera-maya/puerto-morelos/recreation