Hol Chan Marine Reserve became Central America's first marine protected area in 1987, a five-square-mile corridor carved from the Belize Barrier Reef where elkhorn coral forests rise thirty feet from the seabed and nurse sharks patrol a natural channel locals call the cut. The reserve's name derives from Mayan — "hol chan" translates to little channel — and that fifty-yard break in the reef wall creates a nutrient-rich current that draws southern stingrays, green moray eels, queen angelfish, and hawksbill turtles into a density biologists measure in organisms per cubic meter rather than sightings per hour. Four miles south of San Pedro on Ambergris Caye, the reserve operates under Belize's Marine Reserve Regulations of 2000, which prohibit fishing, anchoring on coral, and reef extraction within its boundaries. Full day snorkeling San Pedro Belize itineraries typically bundle Hol Chan's main cut with Shark Ray Alley, a sandy flat where southern stingrays and nurse sharks congregate in water shallow enough that snorkelers float three feet above the animals. Tour operators departed San Pedro's coastline with single-stop trips through the 1990s; multi-stop safaris emerged in the early 2000s when guides began linking Hol Chan to outer reef walls, mangrove channels, and Caye Caulker's leeward shallows. Seven-stop routes now standard across the industry include elkhorn gardens, brain coral formations, turtle grass beds where green sea turtles graze, and channel dives where the reef drops from six feet to sixty in a single swim-through. The reserve sits within the Mesoamerican Barrier Reef System, the Western Hemisphere's longest coral structure and a UNESCO World Heritage Site since 1996. Belize's segment spans 190 miles and shelters over five hundred fish species, sixty-five coral species, and breeding populations of endangered Nassau grouper. Conservation efforts intensified after the 2016 coral bleaching event; Hol Chan's core zones now operate under rotating closures that allow polyp recovery, and the reserve employs eight full-time rangers who enforce the fifteen-dollar conservation fee collected from every visitor. Morning departures between eight and eleven capture the clearest visibility — suspended sediment settles overnight, and wind-driven chop builds after midday. Water temperature holds steady near eighty-two degrees year-round; three-millimeter wetsuits suffice even in January. Full day snorkeling San Pedro Belize tours depart from beachfront docks along Barrier Reef Drive, where skiffs idle in water clear enough to count coral heads from the pier.