Punta Sur, Devil's Throat

Devil's Throat is Cozumel's rite of passage: a coral tunnel that swallows the group in single file, bends downward through the dark, and spits you out on the open wall around 40 m with blue in every direction. The passage itself is short but committing (no turning a group around mid-tube), and the surrounding Punta Sur reef keeps the drama going with deep cuts, black coral, and the chance of a reef shark cruising the point. Bottom time is brief and the ascent is a long, scenic decompression-style drift up the wall shoulder.

The moment you come for: The tunnel exit at 40 m, cathedral-like passages, black coral, big-animal potential at the point.

Topography: Steep coral promontory riddled with tunnels; the Throat is a narrowing passage that exits on the wall face near 40 m.

Current: Current at the island's southern tip can be unpredictable and switch with the tide.

Entry: Exposed southern site; dived only when conditions allow, with prompt descents onto the reef shoulder.

Hazards: Overhead passage, depth at the exit, short no-deco window, current at the point. Not a dive for the unpracticed.

Conservation: Marine-park site; guides limit group sizes through the tunnels.

Nitrox: Worth it here: profiles sit in the range where enriched air meaningfully extends no-stop time (with the training to use it).