Black Rock's northern side sits within a small, sheltered bay formed by the gap between the two main rock outcrops that make up the site, a low reef roughly the size of two tennis courts off Smoky Cape Beach. The bay gives divers protection from all but the calmest-day currents, with depths around eight metres at the rocks dropping gently to sixteen on the surrounding sand, and it is dived as a distinct, separate excursion from the southern side to keep divers within sight of the boat given the modest size of the whole formation. Crevices six to eight metres deep cut into the rock, opening onto small boulder fields and then a reef edge, and the northern side is particularly known for its dense growth of large plate coral — an unusual and attractive feature this far south, reflecting the site's transitional temperate-subtropical position.

The northern side supports an easy, all-levels dive with strong photographic appeal: egg cowries described locally as looking like diamonds on black velvet, resident loggerhead and green turtles including a distinctive three-flippered loggerhead known to frequent the site, large black stingrays and white-spotted shovelnose rays cruising the sand, and moray eels, lionfish and nudibranchs tucked into the crevices. Schooling baitfish and tropical species move over the reef, and grey nurse sharks are an occasional but real possibility given the proximity to Fish Rock and Green Island. Because of its shallow depth, sheltered bay and gentle topography, Black Rock North is regularly used as a relaxed second or third dive on a South West Rocks day, well suited to newly certified divers or as a change of pace from the more demanding Fish Rock sites, and its small footprint makes it easy to explore thoroughly within a single tank.

Boat access from South West Rocks, departing the town boat ramp/marina with Fish Rock Dive Centre or South West Rocks Dive Centre. The run is short — generally 10-20 minutes — as these sites lie closer inshore than Fish Rock itself, off Smoky Cape or between the town and Hat Head National Park. Boats moor or hold-station over the site for a direct descent; no surface swim required.

A shallow inshore site exposed to swell — only diveable, and only passable between the two rocks, on the calmest days. Visibility drops with any groundswell or after rain.

Descend into the sheltered natural bay between the two rocks, work the reef edge where it meets the sand at around 16 m, exploring the six-to-eight-metre crevices and boulders, then finish shallower over the plate coral gardens closer to the rock.

Fish Rock Dive Centre (South West Rocks) — regular boat trips; South West Rocks Dive Centre — daily boat trips.