Andrews Caves on Lamont Reef is described by marine life writers as a huge coral-encrusted wall with lots of caves, some large and intricate and others little more than crevices, at depths of 10-25 m. The current is manageable, and dives can be planned as drifts along the wall. It lies about an hour by boat from the resort on Heron Island.

Turtles, sea snakes, cod, nudibranchs and other small creatures are recorded, and the caves create shaded habitat for soft corals, sponges and cryptic fish. The wall itself is heavily encrusted with coral, making the dive visually rich even outside the caves. Because of its distance from Heron and from the mainland, Lamont is visited only on special trips or by private boats.

It suits divers with Advanced certification or equivalent experience who are comfortable drifting along a wall at moderate depth. The larger caves are described as intricate, so divers should view them from their entrances unless trained and equipped for overhead environments. A torch is essential to appreciate the colour inside.

Lamont sits between Fitzroy and Llewellyn reefs, and a boat trip in the northern Bunker Group can combine it with Fitzroy's sheltered lagoon and The Catacombs on Llewellyn.

Heron Island is 72 km north-east of Gladstone. Fly or drive to Gladstone, then take the Heron Islander ferry from the Gladstone Marina terminal (72 Bryan Jordan Drive; check-in from 7:45 am, departs 9:30 am on scheduled days, about 2 hours), or transfer by seaplane or helicopter. Dive gear is carried on the ferry in addition to baggage.

On the island, the dive centre sits beside the harbour; boats leave the jetty for three dives daily and most Heron Reef sites are 5-15 minutes away. Lamont Reef is about an hour by boat from Heron Island, so it has been dived on occasional long-range trips from the resort; private boats from 1770 or Gladstone take several hours.

The Bunker reefs are open ocean: south-east trades over about 20 knots make the crossing from 1770 or Bundaberg rough and limit diving to the lee (north-western) sides, while the Fitzroy and Lady Musgrave lagoons provide secure anchorages. The best windows are September-December and March-May calms. Tidal currents run strongly around reef edges and through lagoon entrances on springs.

Cyclone season November-April; summer plankton reduces visibility. Currents are described as manageable, allowing dives to be planned as drifts along the wall.

Descend onto the wall at 12-15 m and drift with the current, dropping to 20-25 m to look into the larger caves from their entrances. Ascend gradually along the wall and finish with an SMB-marked safety stop.

No scheduled day trips. Lady Musgrave Experience mentions the northern Bunker reefs (Boult, Llewellyn, Lamont and Fitzroy) as remote sites for special or extended trips, Heron Island Resort has historically run occasional long-range trips to the northern Bunker reefs, and most diving is from private yachts and occasional liveaboards.