Hol Chan Marine Reserve sits at the southern tip of Ambergris Caye, about 6km from San Pedro and accessible by boat in under 30 minutes. The reserve encompasses the full reef cross-section: the backreef lagoon, the reef crest, and the fore-reef slope dropping to deeper water. The marine life is exceptional — grouper, snapper, parrotfish, lobster, sea turtles, and rays are all common sightings.
The reserve is divided into zones, with the main dive and snorkel site in Zone A, a seagrass bed in Zone B where manatees are sometimes seen, and Shark Ray Alley — where nurse sharks and stingrays gather in shallow water — in Zone C. All boats must use the reserve's moorings, and fishing is prohibited throughout. The entry fee is USD 12.50. Every dive shop in San Pedro runs trips here multiple times daily.