SITE DESCRIPTION
OVERVIEW — WHAT MAKES THIS SITE SPECIAL
Christmas Point occupies the north-western tip of Similan Island 9, where the long, sheltered reef of Three Trees / Breakfast Bend on the eastern side gives way to a completely different underwater world. One possible explanation for the site’s name is the Christmas tree worm (Spirobranchus giganteus) — a polychaete whose spiral feeding plumes resemble miniature Christmas trees and grow in dense clusters across the granite boulder surfaces throughout the site. Whether or not that is the true origin, the worms are undeniably a defining feature here and one of the most photographed macro subjects at any Similan Islands site.
The site’s centrepiece is a cluster of massive granite boulders, one of which breaks the surface. Underwater, the boulders create canyons, crevices, and the arch swim-through at around 24 m that are one of the most memorable features of diving in the northern Similan Islands. The arch frames a passageway wide enough for two divers side by side, walls and ceiling draped in orange and red soft corals, with giant sweetlips and large groupers stationed at the exit. Golden gorgonian sea fans span the crevices between boulders throughout the deeper sections. The open north-western exposure brings strong current on the right days, and with current comes life: Napoleon wrasse, giant trevally, and the occasional pelagic visitor circling the boulders in the blue.
DIVE ROUTE / LAYOUT
Divers descend and drift onto the site and head down and north-west along the boulder faces, dropping to 20–25 m where the architecture becomes more complex: canyons, overhangs draped in soft coral, and crevices sheltering ribbon eels and dancing Durban shrimps. At around 24 m the arch appears — a natural granite passageway approached from the east and exiting west into open water. Groupers and giant sweetlips are almost always present inside; sea fans frame the opening on both sides. Experienced divers can continue north-west to the deeper boulders at 30–40 m, where leopard sharks rest on the sandy floor and whitetip reef sharks cruise between the rock bases, but usually NDL restrictions mean that you are shallowing up after this.
The ascent follows the boulder system back towards the island, rising through the 15–20 m zone where Christmas tree worms are most abundant on the rock surfaces. The shallow hard coral garden at 5–10 m makes for a rewarding safety stop. Groups on stronger-current days may drift north and finish closer to North Point — a natural extension if conditions allow.
HIGHLIGHTS & UNIQUE FEATURES
The arch swim-through at around 24 m is the defining feature of Christmas Point and one of the most celebrated single underwater formations in the Similan Islands. Large enough for two divers side by side, interior surfaces covered in soft corals, and giant sweetlips and groupers almost always stationed at the western exit. Drifting through on a gentle current and emerging into open blue water flanked by those fish is an experience divers describe for years afterwards.
Christmas tree worms (Spirobranchus giganteus) are found here in exceptional density and colour variety — vivid yellows, electric blues, purples, and reds growing in tight clusters from the granite boulder surfaces. They are found across the Andaman Sea, but their profusion and colour variety here as exceptional relative to other Similan sites. They retract instantly when approached but re-emerge within seconds: approach slowly, pre-focus, and wait.
The golden gorgonian sea fans in the boulder crevices at 25–35 m are among the largest in the Similan Islands, some spanning more than 1.5 m across. Napoleon wrasse (Cheilinus undulatus) are reliably present here in higher frequency than at most Similan sites — their size, curiosity, and tendency to approach divers make them one of the most impressive encounters the site delivers.