Christmas Point
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.
Off island 9 at the archipelago's northern end, Christmas Point arranges its granite into ridge lines and a run of archways that divers thread with the current at their backs. Big gorgonians and bushy black coral decorate the deeper passages, ribbon eels flag from the sand between boulders, and Napoleon wrasse make stately rounds while jacks harry the fusilier schools above. Leopard (zebra) sharks once lazed on these sand flats routinely; sightings are scarcer now, an honest barometer of regional pressure, though the odd individual still appears. It is the north's classic final-morning dive before boats turn for Koh Bon.
The moment you come for: Archway sequences, ribbon eels and Napoleon wrasse, northern-Similan granite at its prettiest
Topography: Granite boulder ridges with archways, sea fans, and sand channels
Know before you splash
Hazards: Current through the arches and depth on the outer boulders.
Conservation: Standard park protections; the sand-resting sharks that remain deserve wide, calm berths.
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
Giant Trevally
Leopard (Zebra) Shark
Napoleon (Humphead) Wrasse
Nudibranchs
Ribbon Eel
For photographers
Wide angle: ★★★★★ · Macro: ★★★☆☆ — editors' 1–5 rating of what this site gives each style of shooting