Cebu

Cebu sits at the intersection of the Visayan Sea to the north and the Bohol Strait to the south, a 196-kilometre island that has been a trading and maritime crossroads for longer than recorded Philippine history. The surrounding waters are mixed semidiurnal — two high tides and two lows each day, but unequal in height, which is the characteristic signature of much of Southeast Asian tidal behaviour. Mean range at Cebu City runs 0.8 to 1.0 metres above Chart Datum; around Mactan Island the range sits close to 0.9 metres. By global standards this is microtidal to mesotidal — modest, but enough to matter for reef access and harbour operations. The tidal exposure of Cebu's fringing coral reefs is the fact that structures most coastal activity. At low water, reef flats emerge or approach the surface around Mactan and along the southwest coast, governing when snorkellers and divers can safely enter. Moalboal on Cebu's southwest coast is where the island's underwater reputation is concentrated — the sardine run off Panagsama Beach, where millions of Sardinella lemuru move in a dense, shape-shifting school just metres from shore, is one of the more extraordinary marine spectacles in Southeast Asia, and one of the few accessible without a boat. That phenomenon is current- and seasonal-driven, not tide-dependent, but it coincides with a coast where limestone cliffs drop directly into the sea and dive access is tide-aware. For tide data on Philippine waters, the authoritative source is NAMRIA — the National Mapping and Resource Information Authority — which publishes official tide tables for Philippine stations. Tide predictions on this site use Open-Meteo Marine, a gridded global ocean model accurate to within approximately ±45 minutes on timing and ±0.2–0.3 metres on height.