In the 40 years since famed biologist and underwater explorer Jacques Cousteau proclaimed the Great Maya Barrier Reef, just off the coast of Cozumel, to be one of the finest diving areas in the Caribbean, Mexico’s largest island located 12 miles from the Yucatan peninsula has become one of the top Scuba diving destinations in the world.

I wouldn’t call myself an expert diver by any stretch—officially I am an SSI (Scuba Schools International) level 3 diver with just over 30 logged dives (most of them drift-dives in the cold Niagara River with low visibility). I don’t plan vacations around diving or haul my gear around the world, but if you are a diver and have only one day in Cozumel…you go diving.

Like most visitors to Cozumel, my day started early at the once-sleepy fishing village, San Miguel, where I easily caught a cab to the dive shop at the AAA Four Diamond resort, Presidente Intercontinental. After showing my dive credentials and getting fitted with gear and a wetsuit, I joined a small group for two dives at the magnificent coral mountain called Palancar. The Palancar Reef is just one of several reefs in the massive system and is famous for giant canyons of coral and spectacular walls that drop to the depths of the ocean.

The first dive seemed to go by in an instant, as our dive master led us around, over, and through a spectacular maze of coral fingers. With much more marine life and nearly 100 feet of visibility, our second dive was truly unforgettable. Divers can choose dozens of reputable dive operators on the island, but the island can also be an underwater adventure for non-divers as well.

The fist dive, our deepest at just over 80 feet, seemed to go by in an instant. Our dive master led us around, over, and through a spectacular maze of coral fingers. After a short break for lunch, our shallower second dive had much more marine life and, with nearly 100 feet of visibility, was truly unforgettable. There are dozens of reputable dive operators on the island and many cruise ships offer dive excursions, but the island can also be an underwater adventure for non-divers as well.

One of the most popular tourist playgrounds on Cozumel is Chankanaab National Park. Just a 10-minute cab ride south of San Miguel, you can easily spend your entire day at the park. It offers a gorgeous beach, restaurant and bar, cultural history, and swimming and snorkeling in the crystal clear water of a protected bay. You can also experience the thrill of swimming with dolphins in their natural habitat at the Dolphin Discovery Center.

While simply relaxing away the day soaking up the sun on the beach is clearly an option, the park also offers beginner level scuba diving from the shore and SNUBA (a combination of “snorkel” and “Scuba”) where non-divers ages 8 and older can experience the underwater world of Cozumel in a safe, simulated Scuba experience. With so many options, what will do with your one day in Cozumel?