Stretching roughly from the small town of Punta Bete in the north and extending some 75 miles southward to Tulúm and the UNESCO Biosphere Reserve at Sian Ka'an, the Riviera Maya encompasses a long arc of lovely white-sand beaches pocked with upscale resorts, small villages, dense greenery and, in many places, largely unexplored diving. Hammocks still swing, coral shimmers beneath a hot sun and life much as it has always been still reigns along large stretches of this coast. Playa del Carmen still possesses all the charm of a small Mexican town plus the infrastructure to make any visitor comfortable. There are plenty of qualified dive operators here to take you diving in the ocean or to explore the underbelly of the jungle.

www.sportdiver.com/riveramaya

The Great Maya Reef wends along for 600 miles off the coasts of Mexico, Belize, Guatemala and Honduras like a dream waiting to happen. Clear Caribbean waters and plenty of sun give the reefs what they need; life explodes here. And, of course, there is the cave diving. The Yucatan Peninsula, a limestone firmament pocked underground like Swiss cheese, has become famous for its flooded cave systems and cenote diving. The majority of the 70-some cave systems are concentrated along the Yucatán Caribbean coast between Puerto Aventuras and Tulúm, representing what may be the world's best and most extensive cave-diving area. At least three enormous water-filled caves are located here — Ox Bel Ha, Nohoch Nah Chich and Dos Ojos — amphitheaters of pinch-me 200-foot clarity, offering flight with fins. More than 200,000 feet of surveyed tunnels have been explored in these cave systems alone — so far. Since the 1980s over a million feet of cave passages have been discovered on the Yucatán, and new discoveries, like the aptly named Dreamgate cenote, are trumpeted on a regular basis.

For travel package informationwww.sportdiver.com/divemexico

Don't expect solitude everywhere. The Riviera Maya is Mexico's fastest-growing resort area — hotel conglomerates around the world are queuing up, resorts spring up like kudzu and towns like Playa del Carmen are changing almost overnight. Huge crowds of day-trippers already descend from Cancún to explore archaeological sites, theme parks, Maya ruins and nature reserves. When the visitors leave, though, the palms still rustle quietly, the reefs shine and the empty hammock beckons you.