Whale shark swim in Cancun and Isla Mujeres

When the season runs

The whale shark season in the Mexican Caribbean runs from mid-May to mid-September, peaking in July and August. During those months currents concentrate plankton near the surface off Isla Mujeres and Isla Contoy, and the whale sharks arrive to feed.

May and the first half of June: season opening, fewer boats and good sightings. July and August: absolute peak, with the largest aggregations. First half of September: closing, with excellent days and far fewer people.

Outside those months the activity is not offered. If someone sells it to you in January, be sceptical.

How the trip works

We leave early from Punta Sam pier, north of Cancun, and head for the aggregation zone. Travel time depends on where the animals are that day.

Once there, you enter the water in turns: two swimmers plus the guide, always with a life jacket and always respecting the minimum distance set by the protected area regulations. You do not touch the animal, do not cut across its path and do not use flash.

Everyone gets several turns. On the way back we usually add a reef snorkel stop.

This is snorkelling, not diving: no certification or experience required. Just comfort in the water.

Shared trip or private charter

The shared trip is the standard option: a boat with other travellers, from US$159 per person. Small groups and orderly turns.

The private charter books the whole boat for your group of up to ten, at US$1,599. The real advantages are the flexible schedule — you can leave ahead of the fleet, when fewer boats sit over the animals — and far more water turns per person.

From six people up, the charter usually works out better value than the shared trip.