Palm-fringed white-sand beach along the calm, clear shallows of Marovo Lagoon.

Coral Triangle · Solomon Islands

Marovo Lagoon

Step off a jetty into the world's largest lagoon, or cross to open ocean

Photo: Xplore Dive · CC BY 2.0

Marovo is the largest saltwater lagoon in the world, enclosed by a double barrier reef running for a hundred kilometres along New Georgia. The passages that cut the barrier flush enormous volumes of water and concentrate fish on their corners, while the lagoon side holds sheltered coral gardens and mangrove-backed shallows. Uepi Island sits directly on the barrier, so divers can step off a jetty into the lagoon or cross a few metres of sand to a wall dropping into open ocean.

About diving in Marovo Lagoon

Days here run on the tide rather than the clock. Guides read the exchange and pick the passage dives to match it, so the boat may leave early one morning and mid-afternoon the next, usually for two dives with everyone dropped up-current and collected wherever they surface. Rides are short because the barrier is only minutes away. Between boat trips divers go in from the beach in buddy pairs, so a week here can finish with more shore entries in the log than boat dives.

The three environments feel like separate destinations. On the ocean side the barrier falls away as a steep hard-coral face with fans on the overhangs and open blue off the shoulder. In the cuts the reef narrows into ridges and rubble slopes that funnel the tide and stack fish on the corners. Inside, the lagoon is a maze of patch reefs and coral heads rising off pale sand, calm enough to dive in almost any weather and noticeably greener than the ocean side, where the clearer water sits.

A passage dive is the one profile that crosses all three. Run on the flood, it starts outside in moving water, works along the corner where the current line concentrates fish, then releases into the cut and finishes over coral in near-still shallows — a single tank that begins in the ocean and ends in the lagoon. When the tide is wrong, guides fall back on the undercut sections of the barrier, or on the sand patches, coral heads and mangrove edges inside, which is where macro shooters spend their week.

This suits divers who value reef quality over choice. Infrastructure is thin — a handful of operations, no dive town, no alternative if the weather turns, and two flights plus a boat transfer to get here — but you rarely share a site with another group. Newer divers can fill a week inside the lagoon and on the sheltered reef tops, while anyone comfortable in moving water gets the passages. Wreck divers will find little; that is Guadalcanal's department, further east.

When to dive Marovo Lagoon

Month-by-month season rating for Marovo Lagoon
JanFebMarAprMayJunJulAugSepOctNovDec
FairFairGoodPrimePrimePrimeGoodGoodGoodPrimePrimeGood

Apr–Jun and Oct–Dec are calmest and clearest; Jan–Mar is the cyclone and wet season with rougher crossings.

Getting there

Honiara is the international gateway, followed by a domestic hop to the Seghe airstrip on New Georgia and a short boat run up the lagoon to the island lodges. Diving is small day boats plus shore entries on the house reef, and liveaboards out of Honiara take in the lagoon on their western itineraries.

Wildlife calendar

Grey reef and whitetip sharks, trevally and barracuda gather on the passage corners when the tide runs, with napoleon wrasse and turtles over the reef tops through the year and mantas an occasional visitor at the cuts. Nudibranchs and other macro are easiest in the sheltered lagoon shallows, which also work after dark. April to June and October to November rate highest for ocean-side clarity.

Dive types & marine life

  • Wall
  • Reef
  • Drift
  • Coral garden
  • Muck & macro
  • Pelagic & blue water
  • Reef sharks
  • Pristine corals
  • Sea turtles
  • Napoleon wrasse
  • Trevally & jacks
  • Barracuda
  • Manta rays
  • Nudibranchs
  • Macro critters

Notable dive sites in Marovo Lagoon

  • Uepi Point

    Barrier corner where lagoon water meets ocean, with sharks and jacks.

  • Charapoana Point

    Wall and drift on the passage edge, dropping past 40 m.

  • Elbow Cave

    Cavern in the barrier reef at 20 m with sweepers and soft coral.

  • Welcome Jetty

    Shore-entry house reef with resident fish and easy night diving.

  • Landoro Passage

    Tidal cut through the barrier, drifted into the lagoon on the flood.

Photos from Marovo Lagoon

  • Xplore Dive · CC BY 2.0

Dive videos

SCUBA Diving at Uepi Island · Fish Guy Photos on YouTube

Uepi Island Resort - Marovo Lagune - Diving Amazing Solomon Islands · underWATERcam - Your Window to the Ocean & Nature on YouTube

Photo credits

Similar destinations

Coral Triangle

Raja Ampat

Indonesia

Manta rays hold at cleaning stations in the world's most biodiverse reef system.

27–30°C · vis 25mintermediate

Coral Triangle

The world's third-largest atoll, and a wall running the length of Selayar

27–30°C · vis 40mintermediate

Coral Triangle

Apo Reef

Philippines

The world's second-largest contiguous coral reef, closed to fishing

27–30°C · vis 40mintermediate

Coral Triangle

Scalloped hammerheads school along a wall that drops 2,000 m

27–30°C · vis 45madvanced