South Boulder Wall is the southern counterpart to North Boulder Wall, sitting a short distance along the same sheltered, north-western face of South Solitary Island and sharing essentially the same gentle topography: a shallow platform around 10-12 m spilling over into a boulder-strewn slope that bottoms out near 18 m. Having two moorings along one continuous wall gives Jetty Dive Centre flexibility to spread boat traffic on a busy day, or to run a single longer drift dive covering both sites when conditions and diver experience allow. Fish life here mirrors North Boulder Wall closely — divers who have described the site simply note there being more fish than you can readily take in on a single dive, from schools of silver trevally and tarwhine to resident red morwong, snapper and the crayfish that shelter throughout the boulder field.

Giant cuttlefish move onto the reef seasonally, and turtles are a near-certain sighting given how much of this face of the island they use for resting and grazing. Because the wall faces away from the prevailing swell direction, this is one of the sites least likely to be cancelled by weather, which makes it valuable both as a training and check-out site and as a reliable closer to a day built around the more exposed, current-affected moorings elsewhere on the island. There is little to meaningfully distinguish South Boulder Wall from its northern neighbour beyond its slightly different position along the same wall, and most operators treat the pair as interchangeable options depending on which mooring is free or which direction suits the day's boat traffic and current.

For a diver's purposes, expect the same easy depths, sheltered conditions and dense, colourful reef-fish population found at North Boulder Wall.

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 the southern mooring to 10-12 m and drift the boulder wall toward North Boulder Wall if briefed as a linked dive, checking crevices for crayfish and cuttlefish, and ascend on whichever mooring is closest at the end of the dive.

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.