Cozumel (Mayan: Island of the Swallows) (Kùutsmil in Modern Maya) is an island in the Caribbean Sea off the eastern coast of Mexico's Yucatan Peninsula, opposite Playa del Carmen, and close to the Yucatan Channel. Cozumel is one of the nine municipalities (municipios) of the state of Quintana Roo. Cozumel is a tourist destination for its balnearios, scuba diving, and snorkeling. The main town on the island is San Miguel de Cozumel.
Scuba diving is still one of Cozumel's primary attractions, mainly due to the healthy coral reef marine communities. These coral reefs are protected from the open ocean by the island's natural geography. In 1996, the government of Mexico also established the Cozumel Reefs National Marine Park, forbidding anyone from touching or removing any marine life within the park boundaries. Despite the importance of healthy reefs to Cozumel's tourist trade, a deepwater pier was built in the 1990s for cruise ships to dock, causing damage to the reefs, and it is now a regular stop on cruises in the Caribbean
More information can be found at: http://en.wikipedia.org/wiki/Cozumel