Extreme Drift Diving, CozumelThe drift-dive capital of the northern hemisphere, Cozumel, owes its fast-paced diving action to the channel that separates it from Mexico’s mainland. Famous for down-drafts, Barracuda Reef is widely considered one of the best drifts in the world, with lush and little-visited coral mounts, and a seascape of valleys and mountains that fly by beneath you like some psychedelic conveyor belt. On the main reefs inside Cozumel’s marine park, you’ll find the swiftest currents at sites like Paso del Cedral. Santa Rosa Wall is another rush; here, a sloping mountain turns vertical halfway through the dive — the currents start flowing at precisely the same moment you find yourself marveling at how the wall drops infinitely into the blue. Sensory overload at high speed, to be sure.