Puerto Morelos has the reef closest to shore anywhere on this coast — a few hundred metres out, visible as the line of breaking water from the beach — and it has been a national marine park since 1998. That protection shows: the coral here is in better condition than the stretches further south that spent the same decades under resort pressure.
The consequence is rules. Snorkelling and diving trips must go with a licensed guide from one of the village cooperatives or dive shops, mooring buoys are fixed and limited, sunscreen is not allowed in the water, and nothing may be touched. Boats leave from the pier in the village centre; a two-hour snorkel trip is the standard outing and costs a few hundred pesos.
Divers get shallow coral gardens that suit beginners, plus the Ojo de Agua freshwater vent and the sunken C-56 for people who want something with structure. The cenotes inland — the Ruta de los Cenotes runs west from the village towards Leona Vicario — are the other half of what the shops here sell, and they are less crowded than the Tulum ones.