Bombora Reef rises from the sandy floor of the bay entrance off Longnose Point towards Bowen Island. As the name suggests, the top comes close to the surface – under 5 m – and waves can break on it in swell. What makes the site interesting is its stepped structure: from the flat top the reef descends through four distinct walls, the first to 10 m among massive boulders and swim-throughs, the second to 12 m, the third to 18 m, and a final, less steep drop to sand at about 24 m.

The walls are covered in sponges, sea squirts and gorgonians, and the boulders and swim-throughs shelter leatherjackets, weedy sea dragons, silver sweep, yellowtail, striped seapike and one-spot pullers. Giant cuttlefish are common – McFadyen records one diver describing a very aggressive individual, presumably a territorial male in the winter breeding season.

Operators typically run it as a live-boat drop: divers exit 'parachute commando style' as the boat passes over the reef, descend the eastern walls, follow the sand north and return over the western walls with their large swim-throughs. The profile is flexible, so it suits Open Water divers who stay on the upper steps as well as Advanced divers who explore the sand. It is useful as a secondary site when the offshore seas are too big, as long as swell is not hitting the reef directly. Divers should be aware of breaking water on the top when surfacing and keep clear of it, deploying an SMB so the boat can find them away from the reef.

Charters depart Huskisson (Dive Jervis Bay; boats in Currambene Creek), and private boats launch at Huskisson, Callala Bay or Murrays Beach. Head for the entrance; Bombora Reef lies offshore from Longnose Point extending towards Bowen Island (about 15 minutes from Huskisson). Operators motor over the reef top and drop divers as the boat passes; private boats should anchor on the sand off the deeper eastern walls rather than on the shallow top, and leave a crew member aboard to pick up drifting divers.

The northern shore of Jervis Bay is sheltered from all ocean swell except a large south-easterly rolling in through the entrance, and it is protected from northerly and north-easterly winds by the Beecroft Peninsula, which makes it the standard summer venue when afternoon nor'easters roughen the outer coast. Strong southerly and south-westerly winds blow across the bay and make the northern shore choppy and the crossing from Huskisson wet. Visibility varies considerably with sea state and rainfall – typically 8–20 m.

Tidal currents are weak except near Point Perpendicular and the entrance. Bombora Reef is a useful secondary site when offshore seas are elevated, provided swell is not breaking directly on the reef top.

Roll in as the boat crosses the reef top, head east off the flat top and descend the walls for about 15 minutes to the sand at 24 m. Follow the sand north, gradually shallowing, then turn west/south-west to meet more walls with large swim-throughs before ascending onto the top.

Dive Jervis Bay (Huskisson; boats Avalon and Genesis) runs double boat dives most days, and Deep 6 Diving Jervis Bay / other Huskisson operators also visit; site chosen on the day according to swell and wind.