The tranquil Costa Maya region of Mexico-sandwiched between Mexico's Riviera Maya region to the north and the Belize border to the south-has remained relatively undiscovered. Also known as the Xcalak Peninsula, the Costa Maya is a place characterized by small fishing villages, simple accommodations and open-air restaurants. Dive sites on the pristine reef, part of the biosphere reserve established by Mexico to protect the reef off the Costa Maya region, are still being named. This is an up-and-coming dive destination, however, and the secret is quickly getting out.

Two towns serve as the base of operation for divers, Mahahual and Xcalak, both within easy reach of the world's second-longest barrier reef. Diving is on two corridors of reef running parallel to the coast: The first begins at the surface and slopes down to around 50 feet. A sandy platform separates the first reef from the second, which starts at 50 feet before sloping at a 45-degree angle until the vertical drop-off. Conditions permitting, local dive operators offer excursions to the outlying Chinchorro Bank, a large coral atoll 19 miles from the mainland known for historic wreck dives and lush coral reefs.

Weather: Air temps are in the mid-70s in winter and mid- to high 80s in summer.

Average Water Temp: In winter, water temps are in the mid-70s; in summer, temps are in the mid-80s.

Average Visibility: Vis is usually in the 80- to 100-foot range.

Travel Savvy: A valid passport is required. A departure tax of $25 is usually included in the airline ticket.

PARTNERS Caradonna Dive Adventures