Tanna Coast at Yasur tide times

Tanna is one of the southernmost inhabited islands in Vanuatu, approximately 200 kilometres south of the capital Port Vila on Efate. The island is dominated by Mount Yasur, an active stratovolcano rising to 361 metres on the southeastern coast. Yasur has been in continuous eruption for at least 800 years — one of the longest continuously erupting volcanoes on earth — and its activity is accessible in a way that few active volcanoes are: a four-wheel-drive track runs from the coast road to within 200 metres of the crater rim, and visitors walk the last section on foot to watch lava bomb eruptions from the crater edge. The eruption cycle is rhythmic — explosions every few minutes, lava bombs arcing 50 to 100 metres above the crater rim, the ground shaking under foot with each blast.

The coast nearest to Yasur, at Port Resolution on the island's eastern side, has an entirely different character from the volcanic interior. Port Resolution Bay is a drowned volcanic caldera — the same geological process that formed the volcano also created a circular bay on the coast where a secondary vent collapsed. The bay is approximately 600 metres across, ringed by black lava cliffs and volcanic black sand beaches, and connected to the open sea through a narrow northeastern passage. Captain Cook anchored here in August 1774 during his second Pacific voyage, recording it as a place of volcanic fire and remarkable hospitality from the local population.

The tidal regime at Port Resolution is mixed semidiurnal, with a spring range of approximately 1.0 to 1.2 metres. The bay is sheltered on three sides; tidal current inside the bay is gentle even at springs, rarely exceeding 0.3 knots. The black sand beach on the western side of the bay is the main recreation area. At low water springs, the volcanic rock platforms at the base of the cliff rim expose a thin band of inter-tidal zone — sparse but present, with barnacles, periwinkles, and small fish in the rock pools. The volcanic rock is sharp and uneven; footing requires care.

Thermal vents on the seabed inside Port Resolution are detectable as areas of slightly warmer water — localised temperature anomalies of 1 to 3 degrees Celsius above ambient in the vents' immediate vicinity. The vents are in 3 to 8 metres of water and are visible during snorkelling as subtle shimmer in the water column above the vent points. The bottom is dark volcanic rock and rubble, with limited coral but reasonable fish diversity.

Access to Port Resolution from the main Tanna town of Lenakel (on the western coast) takes 1.5 to 2 hours by four-wheel-drive vehicle on a rough track that crosses the island's interior. The track passes through the ash plain around Yasur — a flat grey landscape where the volcanic ash fall suppresses vegetation — before descending to the eastern coast. The Yasur crater visit is typically combined with the Port Resolution coast as a full-day excursion from Lenakel.

Flight connections to Tanna from Port Vila operate on Vanuatu's domestic airline network; the journey takes approximately 35 minutes. The airstrip is at Whitegrass on the western coast near Lenakel.

Predictions on this page come from Open-Meteo Marine, a gridded global ocean model. Accuracy is typically within plus or minus 45 minutes on timing and 0.2 to 0.3 metres on height — model-derived, not from a local gauge. The local tide authority is the Vanuatu Meteorology and Geo-Hazards Department (VMGD).