Western Visayas

Western Visayas wraps the central Philippine archipelago between the Sulu Sea to the south-west and the Sibuyan Sea to the east, with Panay, Negros Occidental, Aklan, and the smaller offshore islands including Boracay forming the regional grouping. Boracay is a thin seven-kilometre-long island off the north-west tip of Panay separated from the larger island by the narrow Tablas Strait. The tide here is a moderate mixed semidiurnal signal modulated by the Tablas Strait current that runs between the islands and the Sulu Sea exposure on the south-west flank. Mean range at the Boracay White Beach gauge is about 1.4 metres, climbing past 2.0 on the largest spring tides and dropping near 0.6 on neaps. Two highs and two lows of unequal size each day, with the asymmetry shifting toward strongly diurnal at certain lunar phases. The Tablas Strait current can run sharper than the height swing implies, particularly through the narrow Cagban-Caticlan channel that the bangka pump-boats cross hundreds of times a day during peak season. The defining seasonal force is the monsoon split. The amihan north-east monsoon from November through May drives steady wind across Boracay toward White Beach, calming the west-coast swell and turning Bulabog Beach on the east side into one of the great kiteboarding venues of South-East Asia. The habagat south-west monsoon from June through October reverses the wind, opens the west coast to swell, and shifts the windsurf and kite scene to the eastern Bulabog flats. Typhoon-season storm surge can override the astronomical signal completely; Haiyan in November 2013 passed about 200 kilometres south of Boracay and was severe but well below the catastrophic levels at Tacloban and Guiuan further south-east. The Philippine Coast Guard NAMRIA Hydrographic Office publishes the authoritative tide tables.