Twin Rocks Marine Sanctuary

Two rock towers stand off the slope and break the surface at low tide. Everything on this dive happens on and around them, which is unusual on a coast where most sites are a stretch of sand or a length of wall.

You come down the slope and the spires resolve out of the green. Both are covered top to bottom in soft coral, ascidians and tunicates, with anthias swarming over the tops and butterflyfish working the sides. Grouper hang in the shade of the rock. The jacks, when they are in, come through in a body above everything else.

The reef around the towers changes as you move across it. Down at the outer edge, below where the coral stops, tall dark purple stands of Dendronephthya soft coral sit almost motionless in the gloom. Come up onto the reef proper and the hard corals arrive in quantity, more than fifteen genera of them within a few kicks. Shallower again, branching and table Acropora take over and form thickets. Crinoids are the constant at every depth, in colour combinations that look invented.

It is a small site and a dense one, and divers who know it say the same thing about it: one dive is not enough to see it, and two is the sensible minimum.

A monitoring team scored the management of this sanctuary level 4 in 2011, and no other protected area in Mabini scored as high1. The scale runs from a sanctuary that has merely been initiated, through established and enforced, up to sustained, which is the band Twin Rocks sits in and which asks for monitoring and feedback running two years or more. Arthur's Rock and Batalang Bato scored 3. The Cathedral sanctuary scored 2, because fishing inside the boundaries was not being stopped and there were no boundary markers or signs in the water at all. Three sanctuaries declared the same year under the same ordinance, and twenty years later they are not in the same condition.

You can see what the rating buys. Signs are posted, and the anchor buoys here are adequate to keep boats from dropping anchor on the reef, which is not something to assume elsewhere in Anilao. Enforcement is not distant either. The community that manages the sanctuary lives along the shoreline in front of it and challenges anything that looks wrong.

The school of jacks is the other thing, and here it is counted instead of promised. In 2011 target-fish biomass on the survey transect came to 363.5 kilograms per 500 square metres, and the survey put that number down to the school of bigeye trevally it recorded2. Every operator in Anilao advertises jacks somewhere. This is the one that has a number attached to it. What the number does not tell you is whether the school will be there on your Tuesday, and divers have disagreed about that for years.

The hard decision here is which lens to put on, and everybody who dives it says so. Wide angle has the two spires, the Acropora tables and the jacks. Macro has a field of Euphyllia coral green enough to be the thing people remember from the dive, ribbon eels in both blue and black, jawfish, giant frogfish, bubble-coral and whip-coral shrimp, and enough nudibranchs that people arrive expecting them. One diver counted six clownfish in six differently coloured anemones on a single dive. Guides on this site have been described as slightly underemployed, because the subjects are found before anybody has to look for them.

Do not expect the water to help. Visibility is average at best and the reason is the same reason the crinoids do well: the water carries a heavy particulate load, which feeds them and takes the contrast out of a wide-angle frame. Five metres is a normal bad day. That is not a fault of the site so much as a description of it, and it is why the macro answer wins as often as it does.

Shoot from the water column. The shallow part of this reef is the part that has measurably lost ground, and settling onto it for a better angle is the exact mechanism.

On a shore entry, swim out in mid-water and descend once you are clear of the reef. Do not stand, kneel or kick your way down over the reef flat.

That is the most useful sentence on this page, and it comes from the monitoring record. Hard coral cover on the shallow reef fell from 57.8 percent in 2001 to 44.1 percent in 2011, a drop large enough to be statistically significant, and the survey attributes it to coral damage caused by divers and snorkellers during shore entry dives3. Over the same decade, on the same reef, under the same protection, the deep coral went the other way and increased. Nothing about the sanctuary changed between the two zones. The only difference is where people put their fins, and the shallow zone is the one they can reach on foot.

Fish here are used to people, and at least some of that is being fed. A survey team recorded the batfish as unusually friendly and suspected fish feeding behind it. Enjoy the close approach and do not add to the habit.

A banded sea krait has been found foraging among the rocks. It is one of the most venomous animals in these waters and it has no interest in divers whatsoever. Give it room, keep its route to the surface clear, and let it work.

Depth is the quiet one. Most of the dive sits between 5 and 18 metres, but the reef carries on to about 22, and a photographer on a small subject will find the number before they notice it. Both dives logged here ran past an hour. Set a maximum before you go down, and ascend on the mooring line where there is one, since boats work above this site more than most.

Then the part that feels theoretical on a shallow training reef. No recompression chamber is confirmed operating in Anilao. The nearest one evidenced as working is in Metro Manila, roughly 140 kilometres and two and a half to three hours by road, and the road only starts after a fifteen to thirty minute boat ride back to shore. This site is on the Mabini mainland, so at least there is no strait crossing on top of that. The emergency number to hold is DAN Asia-Pacific, +61 8 8212 9242. An easy site is exactly where that chain gets forgotten, which is the reason to say it here and not only on the deep ones.