Elles Cave is on the ocean-facing southern headland of Jervis Bay, just south of Pyramid Rock and Bowen Island, in the waters of Booderee National Park. McFadyen calls it a very interesting dive site: an L-shaped cave with its main entrance at 17 m that shallows to about 8 m as it exits into a small bay. Good diving is also found at the head of the bay and throughout its main section, so the cave forms the centrepiece of a broader dive rather than the whole of it.

The cave is wide and short enough to be approachable for Open Water divers with a torch and good buoyancy, and the change in depth from entrance to exit gives a pleasing sense of moving through the headland. Its walls carry sponges and encrusting life, and bullseyes and eastern blue devilfish shelter inside, with wobbegongs on ledges. In the bay, kelp and boulders hold blue groper, leatherjackets and wrasse, and the southern headland's clear oceanic water often gives excellent visibility. The Marine Life Network lists the depth range as 8–17 m and notes good diving adjacent to the cave.

The site is more exposed than Bowen Island, so it needs small swell and is best on winter westerly days; surge in the shallow exit is the main hazard when any swell is running. It is often combined with Spider Cave, a short distance south, for two very different cave dives on the same trip. The waters are within Booderee National Park, where marine life is protected.

Charters depart Huskisson (Dive Jervis Bay; boats in Currambene Creek). Private boats can launch at Murrays Beach ramp in Booderee National Park (park pass required), which is the closest ramp to the southern headland. From Murrays run out through the entrance between Bowen Island and the mainland only in flat seas at high tide (boats under 6.5 m), otherwise go around the north of Bowen Island; Elles Cave is on the southern headland a short distance south of Pyramid Rock and north of Spider Cave, about 25 minutes from Huskisson or 10 minutes from Murrays.

Anchor off the small bay; the main cave entrance faces the open water at 17 m.

The southern headland of Jervis Bay (Booderee National Park's ocean coast) faces east and south-east and takes the full force of southerly and south-easterly swell. These sites need swell under about 1–1.5 m and are best in westerly or north-westerly winds – typically winter – when the cliffs give a lee. North-easterly winds are generally fine on this coast but make the run back across the bay choppy.

Visibility is usually good (15–25 m) in oceanic water; currents can be strong further offshore.

Enter the cave at its 17 m main entrance and follow the L-shaped passage as it shallows towards the 8 m exit into the small bay. Explore the head of the bay and the main section around it, then return outside along the wall to the boat.

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. Visited less often than the Bowen Island sites because of the extra distance.