The Split is a deep reef just south of Jibbon Head, a few hundred metres off Royal National Park, named for the crack that runs through it. The reef is flat-topped and covered in kelp, dropping vertically to the sand. Its defining feature is a crack running north–south for a good distance, about four metres deep and two metres wide, with its floor at about 22 m; smaller cracks branch off at right angles, and there are small swim-throughs and caves along the walls.

The average depth is about 26 m, with sand at 25–28 m in different areas. Storms in 2023–24 moved sand around and exposed rock formations previously hidden. The site is known for rare small creatures as much as for fish.

Common sightings include kingfish, bream, blue gropers, flathead, eastern blue devilfish, several wrasse and Port Jackson sharks, especially in winter. The rarer finds are the draw: stargazers, pygmy pipehorses, upside-down pipefish just 50–60 mm long, donut nembrotha nudibranchs, purple ascidians, weedy sea dragons and many other nudibranchs. Visibility is usually good and often exceptional, 15–20 m and sometimes 35 m, because this coast sees little runoff.

The depth keeps surge away, but it also limits bottom time to about 22–28 minutes on air, followed by a mandatory safety stop of at least five minutes; a current from the north sometimes adds to the challenge. The site is only minutes from Port Hacking but, with no charter operating there now, is a private-boat or club dive. It suits experienced Advanced divers, ideally on nitrox, and macro photographers who want to hunt for rare animals.

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. The Split is just south of Jibbon Head, 5–10 minutes from the Port Hacking entrance.

McFadyen's GPS for the southern end is 34° 05.3908' S 151° 10.4425' E and for the northern end 34° 05.3383' S 151° 10.4857' E. For the southern end use his house mark and anchor about two seconds after the house disappears (medium boat); for the northern end line up the house with the vertical crack to the right.

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. At 22–28 m the site is generally free of surge, but a current sometimes runs from the north. Visibility is usually good and often exceptional – 15–20 m and 35 m not unknown.

Storms in 2023–24 shifted sand and exposed previously buried rock.

Descend to the reef top, drop into the main north–south crack at about 22 m and follow it, looking into the side cracks, small swim-throughs and caves, then come out and follow the vertical wall back along the sand at 25–28 m. Allow 22–28 minutes on air with a computer and at least a five-minute safety stop.

Nitrox recommended.

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