Despite its name, the biggest fish in the ocean is also one of the gentlest. Whale sharks, which can grow to about 40 feet, are filter feeders, and eat mostly microscopic plants and animals like plankton and small fish. The warm summer months in Isla Mujeres, Mexico, draw them in droves for a feast on seasonal spawning bonito (Atlantic tuna). No scuba diving is allowed during the aggregation, so you’ll need only your snorkel, mask and fins for a front-row seat to this spectacle at the surface.

WHEN TO GO: May to September

WHERE TO GO: Pro Dive Mexico: prodivemex.com

WHAT TO WEAR: Looking for some whale-watching dive gear?

Love sharks? So do we. Visit the Sharks section of our website.