Cozumel and its surrounding reefs are among the world’s most popular diving spots.

The sites have fantastic year-round visibility (commonly 30m or more) and a jaw-droppingly impressive variety of marine life that includes spotted eagle rays, moray eels, groupers, barracudas, turtles, sharks, brain coral and some huge sponges.

The island can have strong currents (sometimes around 3 knots), making drift dives the standard, especially along the many walls. Even when diving from the beach you should evaluate conditions and plan your route carefully, selecting an exit point down-current beforehand, then staying alert for shifts in currents. Always keep an eye out (and your ears open) for boat traffic as well.

There are scores of dive operators on Cozumel. All limit the size of their groups to six or eight divers, and the good ones take pains to match up divers of similar skill levels. Some offer snorkeling and deep-sea fishing trips as well as diving instruction.

Prices are usually quoted in US dollars. In general expect to pay anywhere between US$100 and US$115 for a two-tank dive (equipment included) or an introductory 'resort' course. PADI open-water certification costs from US$350 to US$420.

Multiple-dive packages and discounts for groups or those paying in cash can bring rates down significantly.

If you encounter a decompression emergency, head immediately to the hyperbaric chamber at Cozumel International Hospital.

If diving is your primary goal, you may want to time your trip for September or October, when weather conditions are ideal. Severe weather can affect turbidity and prevent the boats from leaving, among other hassles.