The Apartments takes its name from the stacked rectangular blocks of sandstone that lie along the outer edge of Long Reef's northern plateau, sitting on one another like the floors of a block of flats, with kelp on the roofs and dark spaces between. The site is continuous with Long Reef Wall to the south and shares its plateau-and-drop-off structure: reef top at 8–10 m, a wall with caves and swim-throughs, boulders and sand patches to about 21 m. What sets it apart is the Valley, a wide gutter in the reef that has been a grey nurse shark aggregation site for as long as Sydney divers have been coming here.

In the 1980s hundreds were reported; numbers crashed with spearfishing and by-catch, and the species is now critically endangered on the east coast, but the Valley still gathers 10–25 or more sharks, with animals present year-round and numbers building from December to a peak in April and May. Big Rock, a lone boulder 30 m east of the Valley mouth at 21 m, is where the larger sharks and bull rays often hold. The Cathedral tunnel, the longest swim-through in the area, lies between the Apartments and the Wall, and its southern pomfret schools are so dense they darken the passage.

Beyond the sharks the fish life is exceptional: southern pomfret in thousands, kingfish, bonito and mackerel tuna hunting over the drop-off, old wives under ledges, blue, green and brown groper, giant cuttlefish and octopus in the crevices, wobbegongs on every second ledge. Because the Valley floor is only 14–18 m and the swim distances are short, the Apartments is an Open Water-level dive that beginners can do with a guide, though operators recommend ten boat dives' experience. Sharks are protected and a code of conduct applies: no touching, chasing or blocking the gutter, no more than a small group in the Valley at once.

It is the best place on the Northern Beaches to see grey nurse sharks and, with the Wall and the Duckenfield alongside, the anchor of any northern charter day.

Boat only. Sydney Dive Charters departs Little Manly boat ramp (Stuart Street, Manly – parking and set-up benches) or Rose Bay public wharf at 07:00 and runs north past North Head, Freshwater, Curl Curl and Dee Why to Long Reef Point, about 30–40 minutes in the Kevlacat; Dive Centre Manly and Pro Dive Manly leave from Manly Cove/Little Manly on similar timings. Private boats launch at Roseville Bridge (Middle Harbour) or from Pittwater (Careel Bay/Bayview, 40 minutes south past Bungan and Mona Vale).

The reef is visible from the surface in good visibility; boats anchor on the plateau in about 10 m and divers descend the anchor line to the wall. No moorings.

Long Reef Point projects further east than any other Northern Beaches headland and takes swell from south through east to north-east. The reef top breaks in anything over about 1.5 m, and surge on the wall is uncomfortable above 1.2 m from the east or south-east; charters cancel or move to North Head when the swell is up. Wind chop from a strong north-easter makes the afternoon anchorage rough, so morning dives are the rule.

Visibility is usually 10–20 m, best in the cooler months (May–September) when the water is clear and 16–18 °C; summer brings warm 22–24 °C water, more plankton and the grey nurse build-up from December to May. Run-off from Dee Why Lagoon and Narrabeen Lakes after heavy rain dirties the inshore water for a few days.

Anchor on the plateau and descend to the wall. Move slowly into the Valley, the gutter where the grey nurse sharks patrol, and settle on the bottom at 14–18 m with the sharks approaching along the gutter; keep to the sides, no strobes in their faces, no chasing. Continue to Big Rock about 30 m east of the Valley mouth at 21 m, loop back along the wall through the Cathedral tunnel if visibility allows, and finish over the boulder field on the plateau with a safety stop on the anchor line.

Deploy a DSMB if surfacing away from the boat.

Sydney Dive Charters – guided double boat dives Thursdays and Sundays (07:00) from Little Manly ramp/Rose Bay, Long Reef sites most weeks in season; Dive Centre Manly – weekend boat dives from Manly; Pro Dive Manly – weekend double boat dives; Frog Dive and Abyss occasionally on club trips. Private boats from Roseville, Pittwater and Rose Bay ramps. Sydney Dive Charters markets the Apartments as its northern grey nurse shark dive and visits most weeks from December to June.