Palancar is the most famous reef on Cozumel, a five-kilometre stretch of coral towers, swim-throughs, caves, and a wall that drops to more than 30 metres. The reef sits along the southwestern edge of the island and is split into named sections — Palancar Gardens, Bricks, Caves, and Horseshoe — each with its own character.
Visibility is usually 30 metres or more, and the steady north-flowing current means most dives are drift dives: you enter, the current carries you, and the boat picks you up downstream. Sightings of large green turtles, eagle rays, and the occasional nurse shark are common. The reef can also be snorkelled from above, though you miss the dramatic structure of the wall.