The usual current direction is parallel to shore from south to north, with speed increasing as you get farther offshore, but the current sometimes reverses direction and occasionally can take a seaward course. Before your dive, arrange with someone on shore to keep watch along the expected drift pathway and to meet you at your exit point at a given time. That way, if you have any problems en route, help can be summoned promptly. Divers with a wide range of skill levels may enjoy Cozumel. For wall dives in particular, an experienced guide will add considerably to your safety and comfort.
Strong currents can create exciting conditions and a few surprises.
When high-velocity water runs into a coral mass, zones of rapid upwelling and downwellings can occur. Being caught in one of the down-draft currents is similar to being flushed down a gigantic toilet, and divers must be aware of their depth and surroundings at all times. Swim sideways to exit a vertical current stream. Novices should never place themselves in any situation where loss of buoyancy control can result in rapid ascents. Diving on or near the lip of sheer walls is safe only for experienced divers and when accompanied by a qualified divemaster.