Coron tide times

Coron is the main town on Busuanga Island at the northern end of Palawan province, and it carries two separate identities: one as the gateway to the Calamian Islands' reefs and beaches, the other as one of the world's premier wreck-diving destinations. On 24 September 1944, a strike force of US Navy Grumman Hellcats and Curtiss SB2C Helldivers hit the Japanese fleet sheltering in Coron Bay in a single coordinated attack, sinking 24 vessels — supply ships, oilers, and a seaplane tender — in an action lasting under an hour. The wrecks now lie in 15 to 40 metres of depth across the bay floor, heavily encrusted after eight decades of coral growth.

The most visited are the Irako (passenger-cargo vessel, 37 m depth), the Okikawa Maru (oiler, stern in 22 m), the Kogyo Maru (armed freighter, 20 to 36 m), and the Olympia Maru (cargo ship, top of superstructure at 16 m). All are penetrable by experienced wreck divers. 0 metres, consistent with the broader northern Palawan coast.

Visibility in Coron Bay is typically 5 to 15 metres — murky by Philippine standards, due to the shallow bay's susceptibility to runoff and particulate matter from the surrounding Busuanga terrain. The best visibility windows are in calm settled weather and at or just after slack tide, when the water column has not been stirred by current. The standard dive briefing for most wrecks is to descend on the last of the flood or first of the ebb — slack is roughly 20 to 30 minutes either side of the predicted high — and to stay within the estimated slack window.

The thermocline inside several wrecks sits at about 18 to 24 metres where freshwater seeps from the limestone create a distinct halocline layer; buoyancy control through the halocline is the main technique challenge on penetration dives. Above the water, Coron Island itself (distinct from Coron town on Busuanga) is owned by the Tagbanua indigenous community, who manage access permits to Kayangan Lake and Twin Lagoon. Kayangan Lake is a saltwater lake trapped behind the island's limestone wall, connected to the sea through underground channels; the water clarity inside the lake is exceptional, typically 8 to 10 metres in the shallower areas.

Twin Lagoon at the base of a cliff on the island's northwest coast has a halocline at about 3 metres depth where the freshwater lens from the limestone sits above the saltwater below; snorkellers cross into the outer lagoon through a low cliff-base opening passable by bangka at mid-to-high tide only. The passage requires a kayak duck or bangka tilt at lower tidal stages; during low spring tides it may be impassable. The Coron-to-El Nido live-aboard route passes through the Calamian Group and is a standard live-aboard itinerary of 3 to 4 days, covering the wrecks, the outer reef drop-offs, and Calauit Safari Park on the northwest tip of Busuanga (home to a population of African ungulates introduced in 1977 as part of a wildlife relocation project).

Night diving on the Coron wrecks — the Okikawa Maru deck and the Olympia Maru superstructure in particular — is offered by specialist operators; the macro life active after dark includes skeleton shrimp, rare cephalopods, and bioluminescent organisms in the still water of the sheltered bay. The best window for night dives is at or just after the predicted low when the water column has settled; confirm slack timing with the dive operator using the PAGASA Coron prediction for the current month. Above the water, the town market on the Coron waterfront opens at sunrise for fresh catch brought in by the overnight fishing fleet — the catch unloads on the incoming tide before the market peaks around 06:30.

3 metres on height. PAGASA is the authoritative Philippine tide source.