Inner Point Perpendicular is the protected, inside face of the great northern headland of Jervis Bay, at the point where the cliffs turn north at right angles. A large pyramid-shaped rock marks the spot, which is why it is also known as Pyramid Rock (not to be confused with the Pyramid Rock on Bowen Island) and as Fish Rock.

The dive runs from sand at 32 m, where a prominent reef and some small rocks begin, up the reef face through 20–25 m and into the shallows at 5 m against the cliff. The cliff is undercut by a number of caves, one of which extends back a considerable distance to the east about 50 m inside the corner. Yellowtail, silver sweep, one-spot pullers and girdled parma are the common fish, and at times quite large schools gather around the pyramid. The reef supports the sponges and encrusting growth typical of the bay entrance.

McFadyen rates it as suitable for all experience levels: the depth can be tailored to the group, the caves are in the shallows, and it is especially good in north-easterly winds when the outer sites are rough. On an incoming tide the site becomes a gentle drift dive along the reef. It is commonly used as a second dive after one of the deeper outer sites such as The Arch or the Point Perpendicular Sponge Gardens, which lie just around the corner. Divers should keep an eye on boat traffic entering and leaving the bay close to the headland.

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; run to the corner where Point Perpendicular turns north at right angles, identifiable by a large pyramid-shaped rock on the shoreline (about 15–20 minutes from Huskisson). Anchor on the reef or run it as a drift on an incoming tide.

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. This site is especially good in north-easterly winds and as a second dive; an incoming tide produces a gentle drift along the reef.

Descend to the sand at 32 m and head south along the reef, then turn east and ascend gradually to 20 m while heading north-east. Finish at 5 m near the cliff face exploring the caves, including one that runs back a long way to the east about 50 m inside the corner. On an incoming tide, let the current carry you along the reef.

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.