Slot Cave is one of the features of the northern shore near The Docks, and Deep 6 Diving lists it as a site in its own right. It is a long, narrow cave – about 60 m – that runs straight into the cliff face at 16–18 m. Despite the name it is wide enough for two divers to swim side by side, and plenty of natural light penetrates, so it feels open and approachable rather than claustrophobic.

The cave's walls host soft corals, sponges and crustaceans, including shrimps and crabs that emerge in torchlight, and eastern blue devilfish and bullseyes shelter in the recesses. Because the cave is flushed by clean water, visibility is often superb. Outside, the reef connects with the kelp, boulders and swim-throughs of The Docks, so divers can link the two in one dive or visit Slot Cave as a highlight of a Docks dive.

The site is protected from summer north-easterlies, which makes it a reliable choice in the season when the outer coast is choppy. At under 20 m and with good light, it suits Open Water divers comfortable in an overhead environment, though a torch is still essential to appreciate the colours and look into the deeper sections. Good buoyancy matters: the floor can silt up and the walls carry delicate growth. As with The Docks, the area falls within the Jervis Bay Marine Park and a sanctuary zone, and the shore is Defence land. The exact position is not published separately, so rely on the operators' marks.

Charters depart Huskisson (Dive Jervis Bay; boats in Currambene Creek), and private boats launch at Huskisson, Callala Bay or Murrays Beach. Cross the bay north-east towards the Beecroft Peninsula shore; Slot Cave is on the northern side of the bay close to The Docks (it is one of the named features in McFadyen's description of The Docks), about 15 minutes from Huskisson. Operators anchor off the cliff nearby.

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. Deep 6 notes that Slot Cave is protected from summer north-easterlies and usually has very clean water.

Descend to the cave mouth at 16–18 m and swim slowly into the slot, two abreast if you wish, using a torch to see the soft corals and crustaceans on the walls. Turn before the cave narrows, exit and explore the surrounding reef or continue to the Docks caves.

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.