Diving in Mexico

Mexico is not one dive destination and it is a mistake to plan it as one. The Caribbean coast, the Yucatan cenotes, the Sea of Cortez and the Pacific seamounts are four separate propositions with four separate calendars, and the only thing they reliably share is that you fly through a Mexican airport to reach them.

The Caribbean side is the accessible one. Warm all year, shallow, easy, and built for volume, it runs from Isla Mujeres and Cancun in the north down past Cozumel to the reefs off Mahahual. Cozumel is the reef diving people travel for; the northern end is where the underwater sculpture is, and where two ex-US Navy minesweepers lie in twenty-five metres of water. A few kilometres inland the limestone opens into flooded cave, and cenote diving is close enough to the coast to be a morning off from the sea.

The Pacific side is the serious one. Revillagigedo, four hundred kilometres out and reachable only by liveaboard, is compared with the Galapagos rather than with anywhere in Mexico. The Sea of Cortez has sea lions and seasonal aggregations, and Cabo Pulmo has a coral reef that recovered after the fishing stopped, which is rarer than any single animal on this list.

Pick the coast first and the month second, because they are tied together. The Caribbean is calmest and clearest from November to April, and that window also covers the winter bull shark season further south. The Sea of Cortez runs the other way, with the warmest water and best visibility from July to November. Revillagigedo runs November to May and puts humpbacks in the water from late January.

Hurricane season runs from June to the end of November and peaks in September. Direct hits are not common but they reshape reefs when they land, and much of what the northern Caribbean coast looks like underwater today was decided by a single storm in 2005.

Most protected areas charge a fee collected by the operator, and the Caribbean parks require a certified guide rather than allowing independent diving. Carry some cash in pesos for park and port charges, and expect Quintana Roo to charge international visitors a state tourism levy before departure.