Tongatapu approaches: Ava Lahi & Piha

Nuku'alofa sits behind a wide spread of reefs on the north side of Tongatapu, and NGA describes three ways through them. Ava Lahi is the principal channel, with a series of ranges. Piha Passage, to the east, is for emergencies. Egeria Channel isn't recommended. Add a westerly set, old mine zones, an occasionally active submarine volcano to the north-west, and a 1990 report of buoys out of position, and this is an approach to make in daylight.

At a glance

The channels

Ava Lahi. NGA says Ava Lahi, the principal approach, was swept in 1942 to 12 m and is larger and deeper than Piha Passage. A series of ranges guides vessels in. A westerly set is usually met, varying with the easterly winds, and it's stronger north of Malinoa and weaker further south.

Piha Passage. NGA says Piha Passage can be used in an emergency but isn't recommended. Streams set east and west, with slack about 2 hours 30 minutes after high or low water at Nuku'alofa (about 3 hours in the narrows, though wind affects this). Currents are irregular, up to about 4 knots.

Egeria Channel. Not recommended (NGA).

Pilots and advice. NGA says pilotage at Nuku'alofa is compulsory for foreign vessels over 500 gt or over 45 m long (and for some tankers and defective vessels), and that any vessel may ask for advice on the best time to transit the channels. The pilot station works VHF 14 or 16. Ports Authority Tonga runs the Port of Nuku'alofa.

Hazards and cautions

• After dark (dated). NGA Pub. 126 reports (1990) that many Ava Lahi buoys were out of position and many lights weak and unreliable, and advises against transiting after dark without local knowledge.
• Hakau Mama'o and Monro Rock. NGA describes Hakau Mama'o, a reef about 7 miles north-east of Niu Aunofo (Tongatapu's north-west point) with a light structure, and Monro Rock, a 7.3 m coral head about 1.5 miles north-east of that light, with an 8.5 m shoal 1 mile north-north-west of it. It warns of shoals just west of the Ava Lahi pilot boarding area.
• Malinoa and Telemachus Reef. Malinoa is a low sandy islet with a light, 7 miles east of Atata. Telemachus Reef, least depth 3.7 m, lies 2 miles north-west of Malinoa and breaks (NGA).
• Duff Reef. 2.5 miles west of the Niu Aunofo light; the sea always breaks heavily on it (NGA).
• North-east of Tongatapu. NGA says shoals cover a considerable area north-east of Tongatapu, including Dido Shoal (least charted depth 4.8 m, breaks in moderate weather) about 13 miles north of the island's east point, and Hyane Shoal (7.3 m). Keep at least 1.5 miles off the east and south sides of Eua Iki, where breaking reefs run about 0.8 mile south-south-east.
• Reefs offshore. NGA says coral reefs extend 9 miles off Tongatapu's north coast with other dangers out to 13 miles, and uncharted reefs have been reported up to 4 miles off the south side.
• Old mine zones. NGA draws attention to old mine zones around Tongatapu. Check the chart.
• Submarine volcano. NGA describes an occasionally active submarine volcano 17 miles north-west of Niu Aunofo. There was 13.7 m over it in 1943, and less may exist since activity resumed in 1999.
• Hunga Tonga–Hunga Ha'apai. NGA Pub. 126 warns that the eruption of Hunga Tonga–Hunga Ha'apai and the tsunami that followed it caused extensive damage to the shoreline and port facilities, so aids to navigation and depths may be unreliable. NGA advises allowing for the strong westerly current around these islands, about 31 miles north of Tongatapu's west end.
• Anchoring and fishing. NGA says a large part of Ava Lahi is prohibited to anchoring and fishing.

Weather and seasons

• Winds. NGA says nearly 60% of winds at Nuku'alofa are from south-east to east. From May to November the strongest winds are usually south-south-east to east-south-east with rain, lasting up to 3 days. From December to April winds are generally easterly, but sudden, violent west and north-west squalls are common.
• Cyclone season (dated). Tonga Meteorological Services' Tropical Cyclone Seasonal Outlook for 2026–2027 (released 28 October 2026, read 30 October 2026) gives the official season as 1 November 2026 to 30 April 2027 and notes that cyclones have occasionally formed outside it. It expects an average season, with 2 to 4 tropical cyclones affecting Tonga and a moderate to high chance of at least one severe tropical cyclone, and the highest risk from January to March 2027. It also reports drought declarations in force for Tongatapu, 'Eua, Ha'apai and Niuatoputapu, with Vava'u and Niuafo'ou under drought warning, so plan your water. NGA Pub. 126 adds that at Nuku'alofa sudden, violent west and north-west squalls are common from December to April.
• Tides. NGA gives the spring range at Nuku'alofa as 1.2 m. Tonga Met publishes tide information on its website.

Ashore

What's within about a 15-minute walk (1.2 km) of each marina, ramp or landing on this page, measured along streets and footpaths in OpenStreetMap. Addresses are from OpenStreetMap where it has one; where it doesn't, we show the name and distance only. Listings as fetched from OpenStreetMap on 28 October 2026; check opening hours before you walk.

This page covers the approach channels. For what's ashore, see Nuku'alofa Harbour.

No marine stores or chandlers are mapped in OpenStreetMap within the walk.

Places, types, addresses and walking distances: © OpenStreetMap contributors (ODbL), fetched 28 October 2026.

About this page

These are free planning notes written by a working delivery skipper from public sources. They are not for navigation. Use the current LINZ chart corrected for notices to mariners, current local notices, official tide tables and local advice. Spotted something out of date? Please use Report a correction below.

Official links

Check these before you go. They beat anything on this page.

• Ports Authority Tonga (Port of Nuku'alofa)
• Tonga Customs: private crafts (advance notice, temporary admission)
• Tonga Meteorological Services: forecasts, tides and cyclone outlooks
• LINZ Notices to Mariners (cover the TO charts)
• NGA Pub. 126 Sailing Directions (Enroute) Pacific Islands (free PDF)
• Tonga Customs forms (Advance Notice of Arrival for small craft, C15 outward clearance)
• Tonga Meteorological Services: marine forecasts
• Maritime NZ: search and rescue in the Pacific (Mayday, beacons)
• TO 502 Approaches to Nuku'alofa Harbour (1:30,000)
• TO 501 Approaches to Tongatapu including 'Eua (1:100,000)
• TO 101 Tonga (1:750,000)

Sources & credits

Need a delivery skipper for this coast? Get a quote from Garry Hartshorne, AMSA Master <45.