Efate and Outer Islands

Vanuatu is a Y-shaped archipelago of 80-plus islands stretching 1,300 km north to south in the southwest Pacific. It straddles two tectonic plates and is one of the most seismically and volcanically active regions on Earth. The tidal regime is mixed semidiurnal throughout: spring range at Port Vila on Efate is approximately 1.1 m above Chart Datum, consistent with the regional pattern. The mixed character — unequal highs and lows — means the navigable window over shallow reef passages changes substantially between the higher and lower of the two daily highs. Efate is the main island, home to Port Vila, the capital. Port Vila Harbour is a deep-water natural port, sheltered by Iririki Island at its entrance. The harbour's sheltered geometry damps short-period wave action even when trade-wind seas are running outside, making it a reliable small-boat anchorage year-round. The reef-fringed south coast of Efate — including Havannah Harbour and the calmer lagoon sections — is where most cruising yachts anchor out and explore. Espiritu Santo (Santo), 250 km to the north, is Vanuatu's largest island and home to Luganville, the country's second city. Santo's defining underwater feature is the SS President Coolidge — a 22,000-tonne American luxury liner converted to a troop transport and sunk in 1942 after striking two American mines at the harbour entrance. The wreck lies in 21–73 m of water, accessible from shore by wading in at the Million Dollar Point beach. Tidal currents over the wreck site run 0.3–0.7 knots on spring tides, which is mild by wreck-dive standards but worth tracking for photographic work at depth. Tanna, in the south, is in a different category entirely. Mount Yasur is an active stratovolcano 12 km inland from the main town of Lenakel, erupting in some form on roughly 60% of days. The coastal approach to Lenakel is exposed to southeast trade-wind swell on its windward face; Port Resolution on Tanna's east coast offers better small-boat shelter. Cyclone season runs November through April. The 2015 Cyclone Pam — one of the most intense Pacific cyclones on record — made direct landfall on Vanuatu and produced catastrophic storm surge on Efate's north coast. Coastal access and beach safety during cyclone season requires real-time meteorological monitoring alongside any tidal planning.