HP Reef
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.
HP Reef earns its Rainbow Reef nickname the moment a torch beam hits the walls: every overhang, chimney, and cave mouth is upholstered in blue, orange, and purple soft coral fed by the channel current. Gray reef sharks and eagle rays hold in the flow off the corners, dogtooth tuna slide past in the blue, and clouds of basslets shiver over the reef top. It is a protected site and a demanding one — when the tide runs hard the smart dive is a tight, guided line along the sheltered face.
The moment you come for: Soft-coral-lined chimneys and caves; sharks and rays riding channel current
Topography: Steep-sided thila cut with caves, chimneys, and swim-throughs
Current: Sits in a channel mouth; currents can be strong and occasionally downward on the outside corners.
Know before you splash
Hazards: Strong, occasionally down-welling current; depth creep along the wall.
Conservation: Protected marine area; reef hooks only on bare rock, never coral.
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
Dogtooth Tuna
Giant Trevally
Grey Reef Shark
Oriental Sweetlips
Spotted Eagle Ray
For photographers
Wide angle: ★★★★★ · Macro: ★★★☆☆ — editors' 1–5 rating of what this site gives each style of shooting