Cathedral Rock

A shallow reef of soft corals, then sand with small coral mounds, then a man-made castle about the size of something from a playground, then the cross. That sequence is the dive, and it is why the site works as a navigation exercise: three landmarks in a row, each one findable from the last.

The cross stands in the gap between two rock masses at around 15 to 18 m, and this is where most of a dive here is spent. Both masses are covered in coral and thick with fish, and the fish arrive as soon as you do, close enough to your mask to be a nuisance. From the cross the dive opens outward along the outer faces, where overhangs and cracks hold shrimps, crabs and moray eels, and gobies sit in the sand between the rocks. Batfish and snapper swing through the gap. Feather stars are on everything.

Light is the reason photographers keep coming back to a shallow reef with no rare animals on it. The gap between the two masses works like a roofless room, and on a clear day with little current the shafts come down through it and backlight whatever is swimming between the walls.

The best coral in Mabini sits on its worst-managed sanctuary. Live hard coral here was measured at 62 percent at 7 to 8 m and 74.7 percent in the shallows at 2 to 4 m, the highest shallow figure recorded at any monitored site on this coast1. Management of the sanctuary rates level 2, the lowest of Mabini's four, because there is no apparent vigilance against fishing inside the boundaries and no boundary markers or signs in place1. Twin Rocks, a few minutes up the same shore, rates 4.

What keeps this reef in shape is the diving. Cathedral is protected by being a popular dive site1, which is a real mechanism and a fragile one, and it is also one of the most dived reefs in the Philippines2.

The fish tell the other half of the story. All-reef fish density fell from 6,095 to 906 individuals per 500 square metres between 2005 and 2011, a statistically significant drop, and the shallow reef holds its coral while lacking target species1. What is left is tame. Klein's butterflyfish were counted at 581 individuals per 200 square metres at the rock and the cross, and fish feeding was evident on the site1. Excellent coral, tame reef fish, and the fish people eat missing.

One more thing marks this reef, in the scientific record rather than the water. Two nudibranchs collected here on scuba at 22 m in February 1995 are now paratypes of Chromodoris alcalai, the species described in 2020 from a holotype taken at Kirby's Rock across the strait3.

There is a caveat on the coral, and it is dated. In May 2010 the water over this reef measured 30.6 C and large areas of the Acropora thickets were showing the first signs of bleaching2. Read that as an observation from 2010, not as a description of the reef today.

Cathedral became a marine sanctuary in 1991, by municipal ordinance of Mabini, together with Twin Rocks and Arthur's Rock1. At about 22.9 hectares it is the largest of the three.

The reef itself may not be original. The rock is described as having been barren, with coral transplanted onto it fragment by fragment until it took, and locally that work is credited to Dr Tim Sevilla, an instructor who ran a dive operation on the beach in front of the site. Treat it as a local account and not a documented one. The outcome is not in doubt.

The cross came afterwards. A concrete cross stands in the gap between the two masses, around 15 to 18 m down, and it is what the site is named for. Local stories tie it to Fidel V. Ramos and say John Paul II blessed it before it was sunk. The year it went in is not established.

Dive it late. Between about half past four and six in the afternoon the reef changes shift: several groups of fish spawn, the day fish go looking for shelter, and lionfish, squirrelfish and cardinalfish come out2. The night dive here is long established and is a navigational one, not a gentle one.

Feed nothing. Fish feeding at the cross is documented and the fish are already tame1, and habituated fish will crowd a mask and a regulator for the first few minutes of the dive. On a reef that has already lost most of its target species, that is worse than a nuisance.

Buoyancy matters more here than the easy grade suggests. The shallow reef carries the highest live coral cover recorded on this coast and it is also where a lot of divers do their first dives after certification. Hover over it and stay off it.

The profile is the other thing the easy grade hides. The reef drops away in small steps with no wall to mark the change, so the depth arrives without anything to notice it against. Watch the computer.

Swimming out from the beach takes six to ten minutes at about 6 m, and how long depends on which way the current is running. The leg to plan is the one back, at the end of the dive on low gas. There are no marked boundaries on this sanctuary either, so nothing in the water tells you where it stops1. The anchor buoys are in and boats use them, so ascend on the line.

Then the part that is easy to leave until it matters. No recompression chamber is confirmed operating in Anilao. The nearest one evidenced as working is in Metro Manila, roughly 140 km and two and a half to three hours by road, and that clock starts after a fifteen to thirty minute banca leg back to shore. Cathedral is on the Mabini mainland and shore-swimmable, so no strait crossing is added and the shore option shortens the first leg. Carry insurance that covers hyperbaric treatment and transfer, check the boat has oxygen, and keep DAN Asia-Pacific on +61 8 8212 9242.