Sunken Island
An isolated pinnacle 10 km off Moalboal in the Tañon Strait, a small plate at 23 to 25 m reached hand over hand down a mooring line through open blue.
Last updated October 2026
The dive
The descent is hand over hand down a mooring line, the only structure at the site, through open water with Cebu behind and Negros ahead. Small sardine-like fish gather above the pinnacle before the top emerges from the blue.
The summit plate shows at 23 to 25 metres, about twelve metres across, and the sides drop away into deep water in every direction. The dive starts at depth and stays there.
The lionfish sit on the plate, big and bunched together. Frogfish and Spanish dancers are named on the rock. Everything else happens outward, where jacks and barracuda work the open water off the edge, and operators advise looking into the blue for the bigger animals.
The way up is the same line.
What makes it special
Pelagic fish are the draw, and one operator singles out their behaviour over their variety: extremely on edge, suggesting predators are close. A free standing shoal in the middle of the strait puts jacks, barracuda and the occasional shark within sight of a diver hanging at the edge of the plate.
Three operators name large lionfish at this site, and one puts them at often twenty in one place. That group on a plate of about twelve metres is what underwater photographers are told to expect.
The shoal sits 10.4 km out in the Tañon Strait, 26 to about 40 minutes by banca depending on the boat. Dive Moalboal and Cebu Fun Divers each list a 200 peso charge for the trip, as of 2026-10, and one operator notes that Moalboal centres rarely make it.
Know before you go
The trip runs only when the surface is calm enough for a boat to hold a mooring in mid channel, and when it is cancelled it is the first dive dropped.
One operator that runs the site asks for experienced Advanced Open Water divers and above, with nitrox certification. Another advises only Advanced divers with many dives. With a working band of 25 to 30 metres, nitrox is worth taking if you have it.
Stay on the line down and up, and brief the down current on the surface: the current has vertical components, and nothing underneath will stop a diver who is pushed down.
Carry an SMB and plan to hang the safety stop in open water, with the mooring line as the only fixed point in view.
Why Dive Sunken Island
What makes this dive site stand out.
- Summit plate at 23 metres
About 12 m across, with the sides falling into deep water
- Descent on a mooring line
Hand over hand, with the line as the only reference down and up
- Up and down currents
One to four knots with vertical components as well as horizontal
- Large lionfish
Photographers go for them, often twenty in one place
- Charged as an extra
Two shops list a 200 peso trip charge, as of 2026-10
Depth & Profile
Location
9.8587°N, 123.3442°E
Conditions & difficulty
Diveable in principle all year. The dry amihan from December to April gives the calmest surface, and surface state decides whether this trip runs at all.
Advanced Open Water is the floor. One operator that runs the site asks for experienced Advanced divers and above with nitrox certification, and another advises Advanced divers with many dives, an experience bar no card expresses.
Summary
Up and down currents to four knots over a pinnacle with no bottom. The mooring line is the only reference on the way down and the way up, so the safety stop is made in mid water, and there is no shallow phase to ease into. The plate is small, and leaving it means open water in a current.
Safety considerations
What can go wrong here, and what divers do about it. Conditions change - take the briefing from the operator on the day.
- Current: One to four knots with up currents and down currents, over a pinnacle with no bottom under it.Descend and ascend on the mooring line, and brief the down current on the surface before anyone gets in.
- Depth: The dive starts at 23 to 25 m with no shallower ground to move onto, and the working band runs 25 to 30 m.Plan a short deep dive around no-decompression time and gas, and take nitrox if you have it.
- Orientation: The top plate is small and everything beyond its edge is open blue.Stay within sight of the plate and the line, and carry an SMB for a mid water ascent.
- Marine life: Lionfish gather on the top plate, often twenty at a time and large.Hover over the rock, keep off it, and give the lionfish room when the current pushes you across the top.
- Surface and boat traffic: The trip depends on a boat holding a mooring in mid channel, and it is the first thing cancelled when the surface turns.Keep slack in the schedule for weather and accept that the boat may not go.
- Remote location: A 10 km boat ride comes before an 82 km road transfer to the nearest recompression chamber, in Mandaue City.Carry insurance with hyperbaric cover, dive conservative profiles, and check that the boat carries oxygen.
Marine Life
Regulations
Tañon Strait Protected Seascape
Dives here go through an operator, who collects the municipal diving fee on each dive. Confirm it when you book. Shops that run the trip bill the municipal fee on every dive and add 200 pesos for this site, as of 2026-10. Confirm both amounts when you arrange the trip.
Frequently Asked Questions
Do Moalboal's diving fees apply at Sunken Island?▾
Shops that run the trip bill Moalboal's municipal fee on each dive and add 200 pesos for the site, as of 2026-10. What is open is whose municipal waters the shoal lies in. One operator places the site in Lambug, Badian, and another describes the boat ride as heading in Badian's direction, while Moalboal's fee and ordinance cover the municipal waters of Moalboal. The boundary out in the strait is not drawn on any chart a diver is shown, so the practical answer is to ask the shop what it collects and why before you pay.
Is slack water needed to dive Sunken Island?▾
One diver recalls it being done at slack water, but that is a single remembered comment, and the figure operators give is one to four knots with up and down components. Treat the full range as the plan, ask the guide on the day what the current is doing, and expect the surface to matter more than the tide in deciding whether the boat goes.
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