Great Wall (Bloody Bay)
Depth is the range from the top of the site to its usual maximum; "recommended cert" is the mainstream-agency level operators usually ask for, not a legal rule. Currents and visibility change daily — treat everything here as planning ranges.
The Great Wall is Bloody Bay's thesis statement. You cross a strip of bright sand in snorkel depth, and then the island simply stops: a face so vertical that looking down produces the small electric lurch of standing on a rooftop ledge. The wall's skin is packed — vase sponges, wire corals, tunicate constellations — and its shallow start means the spectacle works at any depth you choose, including from the surface with a mask. Groupers escort divers along the lip; turtles fly past below like commuter traffic. Few walls anywhere begin so shallow and end so absolutely.
The moment you come for: A sheer face beginning at 6 m, sponge-packed vertical terrain, wall scenery accessible even to snorkelers.
Topography: The reef shelf ends at about 6 m in a wall that drops vertically — undercut in places — into abyssal blue.
Entry: Moored inside the marine park; a short swim crosses the sand shelf to the lip.
Know before you splash
Hazards: The shallow lip hides an instant transition to great depth; set and hold a floor.
Conservation: Bloody Bay Marine Park is mooring-only with strict no-take rules; its condition is the argument for them.
Nitrox: Worth it here — profiles sit in the range where enriched air meaningfully extends no-stop time (with the training to use it).
Who you'll meet
Caribbean Reef Shark
Green Sea Turtle
Hawksbill Turtle
Southern Stingray
For photographers
Wide angle: ★★★★★ · Macro: ★★★☆☆ — editors' 1–5 rating of what this site gives each style of shooting