Cable Trail, at the southern end of South Solitary Island, is named for the remains of an old fishing trawl cable that runs through a pile of boulders and associated rock masses here, a relic of the commercial fishing history of these waters before the marine park's sanctuary zones were established. The mooring sits on a platform of large rocks at about 12-14 m, with the bottom deepening gently to around 18 m toward the south-east, making this a moderate-depth, Open Water-accessible site with genuinely interesting historical texture layered over an otherwise typical boulder reef. Divers who know the site well describe it as holding 'hidden treasures' — unusual and less commonly seen fish species that turn up here more often than at the more heavily dived moorings nearby — alongside more expected sightings of grey nurse sharks moving through the gutters, cuttlefish in season, and a large resident black stingray that has become one of the more reliably spotted individual animals at South Solitary Island.

The boulder piles themselves provide ample shelter for smaller reef fish and invertebrates, and the old cable, now heavily encrusted, has effectively become part of the reef structure it once served. The main practical hazard here beyond the usual considerations is entanglement risk from remnants of the old cable and any additional fishing line that has accumulated around the boulders over the years, so divers should keep clear of trailing material rather than attempting to free it. Conditions at Cable Trail can vary more than at the more sheltered boulder walls, since its position at the southern tip of the island exposes it to swell from multiple directions, but on a good day it rewards a slower, more searching style of diving over the simple spectacle of the busier sites.

Jetty Dive Centre departs from a public floating pontoon wharf on the Coffs Harbour boat harbour, opposite the Attitude Burgers building — check in first at 398 Harbour Drive, Coffs Harbour. It is roughly a 30-40 minute run out to South Solitary Island, 8 km offshore, in the dive centre's RIBs. Private boats launch at the Coffs Harbour public boat ramp inside the breakwall and follow the same course out past the harbour entrance.

South Solitary Island sits in open water 8 km off Coffs Harbour and is exposed to swell from the north-east through south-east; Jetty Dive Centre generally wants under about 1.5-2 m swell to run the outer moorings comfortably, switching to the more sheltered Split Solitary Island (only 20 minutes out) on rougher days. Visibility here is usually the best in the marine park given the distance from any river mouth, and the site's position at the boundary of tropical and temperate water means conditions can change quickly with wind shift. Summer (Nov-Apr) water is warmed by the East Australian Current to up to 26°C, bringing tropical fish, manta rays and, from December, leopard sharks; winter (May-Oct) cools to about 18°C but often gives calmer seas, giant cuttlefish and the peak grey nurse shark season (Jun-Nov, sometimes 30-60+ sharks on Manta Arch).

Humpback whales migrate past between April and November, peaking June-August northbound and September-November southbound. Currents can run strongly on the exposed north-eastern moorings (Manta Arch, Shark Gutters) and are much gentler on the sheltered north-western wall.

Descend to the 12-14 m platform, follow the line of the old trawl cable through the boulder piles looking for grey nurse sharks and the resident large black ray, and work south-east where the bottom deepens slightly to 18 m before returning to the mooring.

Jetty Dive Centre (Coffs Harbour) runs South Solitary Island most days conditions allow, typically a double boat dive; it is the flagship site for the only major dive operator based in Coffs Harbour.