Underwater enthusiasts come to Cancun, Cozumel, Puerto Morelos and other parts of the Mexican Caribbean coast for its clear turquoise waters, colorful tropical fish, and exquisite coral reef. Currents allow for drift dives, deep dives, night dives, wall dives and shore dives while the abundance of offshore wrecks provide exploration dives safe enough for neophytes. The peninsula's cenotes, or natural sinkholes, also provide unusual dive experiences.

For those who are beginners there are a number of courses offered to get you started. The weekend course or PADI resort course qualifies you to dive with an experienced dive master and has become a standard feature in most all-inclusive packages. It includes the basics such as breathing with your underwater equipment, checking your gauges and learning about buoyancy along with some practice time in a dive pool. You may or may not be ready for scuba diving in the open seas after this course. Be cautious and don’t let yourself be pressured into doing anything you are not ready to try.

Longer scuba diving courses can take two or three weeks to complete and will fully prepare you for open sea diving. The PADI Open Water Certification is valid worldwide and allows you to scuba dive anywhere in the world. For the experienced diver many places offer PADI Advanced Training courses such as medic first aid, rescue diver, dive master, and instructor.

There are many dive schools to choose from and its important you find one that you are comfortable with. Look for high safety standards, documented credentials, good equipment and individual attention. Avoid those places that care only about volume. Next to your equipment, your dive master is the most important part of your dive. Make sure your instructor has PADI certification (or FMAS, the Mexican equivalent) and is affiliated with a recompression chamber. These centers aim for a 35-minute response time from reef to chamber and treat decompression sickness, commonly known as "the bends," which occurs when you surface too quickly and nitrogen is absorbed into the bloodstream. Other injuries treated in the recompression chambers include nitrogen narcosis, collapsed lungs, and overexposure to the cold. Make sure your outfit offers some kind of dive-accident coverage such as DAN (Divers Alert Network) insurance.

Diving requires that you be reasonably fit. Be sure to listen to your instructor and don't attempt anything that you're not comfortable doing. When diving be sure to stay at least 3 ft above the reef so you don’t break or damage the reef; it has taken 2,000 years for it to reach its present size. Don’t dive if you have been drinking. And don’t dive within 24 hours of flying.