Some information, from this website:
http://www.cruisemates.com/articles/ports/costamaya.cfm
Exploring Mexico's Costa Maya
by Mary Ann Hemphill
May 7, 2003
There is something new under the Caribbean sun: It's Mexico's Costa Maya, an ancient Mayan maritime trading post, and now a port of call for a growing number of cruise ships. Costa Maya is on the east coast of the Yucatan Peninsula, about 107 nautical miles south of Cancun. The newly-built cruise port of Mahahual has a jetty that can accommodate several large ships.
COSTA MAYA
This is quite a port, offering dining, shopping and recreational facilities. Throughout the day, trams run passengers back and forth between their ships and the pier complex, about 200-300 yards from the dock. There's duty free shopping, of course. One large palapa, or Mexican-style pavilion, houses local craftsmen who are making and selling their wares. Another has a restaurant and bar. Folkloric groups perform in an amphitheater, and there's a swim-up bar in a saltwater pool and a beach-style Mexican restaurant. The style and colors of the port complex are a modern interpretation of the Mayan culture.
Costa Maya is one answer to the Caribbean cruise lines' primary dilemma: where to deploy an ever-expanding fleet, and where to find new and interesting ports to attract a new passenger base and retain repeat passengers. This is especially true with the larger lines in the Caribbean, such as Princess,
Royal Caribbean and Carnival.
The Costa Maya region is home to five of the area's ancient Mayan cities. Some of these are still being rediscovered; all are quite unspoiled. Chetumal boasts one of the best museums of Mayan culture. The impressive ruins at Oxtankah, the first Mayan city, date back to 350 A.D.
Chakchoben
Chakchoben was one of the principal distribution centers for the region's precious woods and jade. It dates back to 360 A.D. and was, until last year, largely unexplored.
Chincorro, a coral reef, offers tremendous snorkeling and diving opportunities. Its size equals that of the island of Cozumel. Divers who explore the reef might see some traces of the wrecks of 16th-century pirate vessels.
Cruise Critic's Costa Maya forum:
http://boards.cruisecritic.com/forumdisplay.php?f=169
Other sites:
http://www.puertocostamaya.com/eng/mayagetaway.cfm
http://www.mayanbeachgarden.com/