Beginner Mexico
Isla Mujeres
The largest known whale shark aggregation, on the surface and freediving
Every summer, a few miles off the coast, hundreds of whale sharks gather to feed on fish eggs at the surface. It's the largest known aggregation of the species, and you experience it freediving, not on scuba.
In this guide you'll find what causes that aggregation, how the activity works and what protocol governs it, what else the island offers (an underwater museum and reefs) when to go, and what level you need.
It's the largest documented gathering point of the world's biggest fish, and a case where regulation arrived after mass tourism already had, and it's still debated whether it's enough.
Geography and access
Isla Mujeres is a small island off Mexico's Caribbean coast, north of the touristy mainland coastline.
In summer, the confluence of currents off this coast concentrates mass fish spawning events. The floating eggs form a soup of animal plankton at the surface.
Whale sharks, which are filter feeders, come to that concentration of food and gather by the hundreds in a small area, feeding almost motionless at the surface.
The activity is done freediving or snorkeling, never on scuba: the animals stay in the first meter of water, and bubbles disturb them.
The island also has an underwater museum of submerged sculptures, created to divert diving pressure away from the natural reef, plus its own reefs just a few meters down.
Access is very convenient: an international airport on the mainland a short distance away, and a short ferry ride to the island.
Keep reading with full access
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