Betio, Kiribati tide times

Predictions: Open-Meteo Marine (MeteoFrance SMOC, 0.08° grid) — heights relative to MSL (not chart datum / LAT). Model-derived.

Model-derived from a global ocean grid. Useful indication; expect about ±45 minutes on average vs. a local harmonic gauge, individual stations vary widely. See /methodology for per-region detail. Not for navigation.

Conditions as of 10:00 local time. Refreshes daily.

Predictions: Open-Meteo Marine (MeteoFrance SMOC, 0.08° grid) — heights relative to MSL (not chart datum / LAT). Model-derived. · Not for navigation.

The angler tradition for major/minor fishing windows: major ≈3-hour windows around moon transit and opposition; minor ≈2-hour windows around moonrise and moonset. Times are Pacific/Tarawa local. Folk tradition, not a scientific forecast.

Next spring tide on Thu 21 May (range 1.1m). Next neap on Fri 22 May.

Spring tides cluster around new and full moons (biggest swings). Neap tides land on quarter moons (smallest swings). See the spring tide and neap tide glossary entries for the why.

Betio is the westernmost islet of South Tarawa — 150 hectares of low-lying coral at the tip of the causeway chain, holding Kiribati's main port, the largest commercial concentration on the atoll, and the most significant Second World War battlefield in the central Pacific. The 76-hour Battle of Tarawa fought here in November 1943 cost over 1,000 American Marine lives and essentially the entire Japanese garrison of approximately 4,500 — among the highest casualty rates per area of any Pacific War engagement. The tidal regime at Betio is identical to South Tarawa: mixed semidiurnal, spring range 0.8 to 1.5 metres. The port operates across the full tidal range — Betio Harbour is the deepest water access on the atoll, used by inter-island freighters, the fishing fleet, and occasional research vessels. At low water springs the approach channel reads 4 to 6 metres depth over the bar; at high water springs the same section is 5 to 7.5 metres. The channel is not tidal-critical for the vessels currently using it, but the outer anchorage ground beyond the passage reef is affected by sea state on the exposed westward fetch. Tide data for Betio comes from Open-Meteo Marine — accuracy ±45 minutes on timing, ±0.2 to 0.3 metres on height. The WWII guns on Betio's seawall are the centrepiece of any historical visit. The Japanese installed four 8-inch coastal defence guns (Vickers Mk I, captured from the British in Singapore) on concrete platforms on the southwestern corner of the island. The guns are positioned at the water's edge; at high spring tide, the base of the concrete platforms is washed by the sea. At low water the surrounding reef flat is exposed to 30 to 50 metres seaward of the platform — the same flat the Marines waded across under fire in November 1943, when the assault was mistimed against an unfavourable neap tide that left the reef too shallow for landing craft. The landing craft grounded on the reef flat 300 to 700 metres from shore; troops waded in under fire across the same flat now exposed at low tide. Walking that flat at low water today makes the tactical problem of November 1943 immediately legible. The Tarawa War Cemetery is administered by the Commonwealth War Graves Commission and contains 22 identified graves of Commonwealth servicemen, plus a memorial to 38 unidentified. The American Battle Monuments Commission memorial is nearby. Neither site is tide-dependent for access. The main Orange Beach — the primary US Marine landing site on Betio's northern lagoon shore — faces the lagoon rather than the ocean; the beach is accessible at any tidal state, with a slightly wider sand exposure at low water. The port of Betio is the functional heart of inter-island shipping for Kiribati. The MV Nei Mataroa and other inter-island vessels load and depart from the main wharf; schedules are published by the Kiribati Shipping Services but are subject to weather and cargo delays. Berthing at the main wharf is at any tidal state due to the harbour depth. The wharf experience is one of the more vivid working-port encounters in the Pacific: copra sacks, fishing gear, returnee passengers, and deck cargo for the outer islands all share the same concrete dock. Observation is possible from the dock perimeter; photography is generally accepted but confirmation with port security is courteous. For the limited cohort of international visitors who reach Betio specifically for WWII history, the combination of the gun platforms, the adjacent reef flat, and the war cemeteries makes a three-hour walking itinerary that benefits from beginning at low water: the reef flat is exposed, the gun platforms are at their most visually complete with the flat extending before them, and the beach landing geometry is most readable. Rising tide in the late morning gives a second useful phase — the water returning across the flat is a direct enactment of what the landing craft would have experienced had they arrived on a different tidal cycle. Sea-level context is unavoidable at Betio. The port, the WWII gun platforms, the war cemeteries, and the dense residential areas are all below 2 metres above mean sea level. King tides already reach the base of the gun platform steps. Under IPCC AR6 projections, a further 0.3 to 0.5 metres of mean sea level rise increases the inundation frequency and area of the platforms themselves. The physical evidence of the 1943 battle — the guns, the concrete, the reef — sits in a landscape where the sea is slowly reclaiming the ground where the battle was fought.