One Spot Reef takes its name from the thousands of one-spot pullers that swarm over the reef, a spectacle even by Royal National Park standards. It lies off the headland north of The Balcony, between The Cutting North Reef and the Underwater Wilderness, about 10 minutes south of Port Hacking. On descent divers land in an area of boulders, with rocks standing off the main reef and a few overhangs.

The large boulders create lots of small caves and even some swim-throughs, and the reef is well decorated with small gorgonians, colourful sea squirts and sponges. The sand edge is at about 21 m, and most of the dive is spent at 14–18 m, which gives about 50 minutes before decompression – generous for this coast. Besides the pullers, McFadyen lists weedy sea dragons, a large bullray, lots of red morwong and yellowtail, and the occasional blue morwong, which is less common in Sydney.

The layout is easy to follow: north along the sand edge for 15 minutes, back south a little shallower, then shallower again to finish near the boat. It is best when seas are calm, making it an excellent fine-weather dive. Like the rest of this coast it has no charter service, so it is visited by private boats and the St George Scuba Club.

Its moderate depth, easy navigation and long bottom time make it a good choice for Open Water divers, second dives and photographers who want to work among swirling schools of fish over colourful reef.

Boat only. Launch in Port Hacking (Gunnamatta Bay/Tonkin Park at Cronulla, Lilli Pilli or Bundeena ramps), run out through the entrance and turn right (south), passing between Jibbon Bombora and Jibbon Head in suitable weather, then follow the Royal National Park cliffs south. Head south towards The Balcony – about 10 minutes – and locate the point on the headland north of it.

McFadyen's GPS is 34° 05.7716' S 151° 09.9771' E. Run in towards the reef and anchor in about 15 m.

The Royal National Park coast south of Jibbon faces east and takes swell from the north-east round to the south-east; southerly swell partly wraps around. These sites lie close to the cliffs, and the shallower ones need calm seas so that boats can anchor near shore and divers are not caught in surge – plan on seas under about 1–1.5 m. Westerly and north-westerly winds give the best conditions; a strong north-easter makes the return to Port Hacking rough.

Visibility is generally good because the coast is far from urban runoff, typically 12–20 m, occasionally 30 m. One Spot Reef is a calm-weather site; at 14–21 m it tolerates a little more swell than The Balcony, but easterly seas still surge through the boulders.

Head east to the sand edge (21 m) and follow it north for about 15 minutes, turn west and head back south at 17–18 m; after 30–35 minutes go shallower (14–15 m) and head north to the boat. About 50 minutes before decompression.

No regular charter – private boat or dive-club (St George Scuba Club) only; no charter boat currently operates out of Port Hacking.