The action is fast and furious as sailfish — which can reach speeds close to 70 mph — chase down and herd schools of panicked sardines off Isla Contoy, a 5-mile-long island located where the Caribbean Sea mixes with the Gulf of Mexico. Istiophorus albicans — sometimes in groups of 12 or more — gather here in December, when the Gulf’s waters cool down. Scuba isn’t permitted, and the encounters aren’t guaranteed, but experienced captains know the best spots. The icing on the cake comes in the form of manta ray, dolphin and whale shark sightings.

When to go: December through March Where to go: Pro Dive Mexico

Still not convinced? Check out this video of sailfish in action.