Koala Reef

The boulders are what you come down onto. They stand on a slope that runs from about nine metres to the foot of the reef, big enough to swim around, and each one carries anemones, soft coral and the small fish that live in both. Between them the ground is coral garden, with sand in the gaps.

Nothing about the gradient is dramatic. It falls at the same easy angle the whole way, which is why guides use it for first dives and why they run it slowly. No wall, no swim-through, no current to fight. What the site gives instead is time. Sixty-two minutes on one logged dive, and the diver surfaced still calling the slope gentle.

Work the upper half and you have the anemones, the clownfish and the hard coral patches. Keep going past the boulders and the ground carries on down with less on it. Most of what anyone photographs here is shallower than the depth figures suggest.

Five clownfish species, each named to species, on one dive. An aquarium biologist diving here in July 2007, in the Philippines for a coral workshop, counted Amphiprion ocellaris, A. sandaracinos, A. perideraion, A. clarkii and A. frenatus in a single pass1. The same dive gave him Goniopora, Fungia and Acropora in abundance, with other large-polyp stony corals he did not stop to list.

Five Amphiprion on one reef in one dive is a specific thing to be able to say, and no other page on this coast says it. It is also one dive, in 2007, and coral fields change over two decades.

The recent record is thinner and points the same way. A diver working the slope for an hour in 2025 reported fifteen species off it, four chromodorid nudibranchs and two frogfish among them, with anemones and clownfish still on the boulders. That is the shape of the site: density in a small, easy space, mostly of things you have to stop and look for.

Anilao sells itself on the current dives out on the strait and on black-sand muck. Koala is neither. It is the one a shop puts you on first, and the one people fall back to when wind has shut the exposed sites.

A reef stonefish has been reported on this slope. On a boulder-and-coral site where photographers work low over the bottom, that is the animal that matters. Hover over the ground instead of settling on it, keep fins clear of the coral, and leave the rock you are framing untouched.

Agree a turn depth before you descend. The gradient here is even the whole way down, with no ledge, no wall and no change of light to signal how far you have gone, which is the exact profile that walks a photographer deeper than planned. The ground carries on falling below the foot of the reef. The part worth the dive does not.

Boats work this stretch all day. Being five to fifteen minutes from most of the coast is what makes the site convenient and also what puts traffic overhead, so carry an SMB and deploy it before you leave the bottom.

The boat leg is the short part of the evacuation chain here, and that is worth knowing precisely because the rest of it is long. From the Mabini side a casualty is ashore in fifteen to thirty minutes, and the driving starts there. Nobody can point to a working recompression chamber anywhere in Anilao, and the nearest one anybody can evidence is in Metro Manila, 140 kilometres away at two and a half to three hours. Short boat, long drive. Two things to settle on the boat and one to put in your phone: what oxygen is aboard, whether your policy pays for a chamber and the journey to one, and DAN Asia-Pacific on +61 8 8212 9242.