Blue Devil Cave is one of the named Bass Point sites promoted by the NSW tourism body and Shellharbour Scuba and Photography Centre, and it has a particular following among macro photographers. Its name comes from the eastern blue devilfish that shelter in the cave and overhangs – a striking, electric-blue-spotted fish that is a signature species of the NSW rocky reef.

The site's real claim to fame is the Sydney pygmy pipehorse, a tiny, well-camouflaged relative of the seahorse that lives among algal turf and was only formally described in 2021. Bass Point is one of the best-known places to see it, and Blue Devil Cave is described as renowned for sightings. Finding one requires patience, excellent buoyancy and usually a guide who knows the individual animals' habitats. Around the cave the usual Bass Point cast is present: weedy sea dragons, giant cuttlefish, blue groper, bull stingrays, and in season grey nurse sharks.

It is best approached as a guided dive rather than an independent exploration, both to find the site and to minimise disturbance to the pipehorses, which are easily damaged by careless finning or over-zealous photography. Divers should avoid touching the substrate and limit strobe use on individual animals. Because it shares the northern side of Bass Point with The Gutter and the Gravel Loader, it benefits from the same shelter from southerly weather, and it can be combined with those sites on a day of shore diving from the reserve.

From Sydney take the M1/Princes Motorway south past Wollongong (about 105 km, 1.5 hours), take the Shellharbour exit and follow Shellharbour Road to the Shellharbour Workers Club, then turn right onto Boollwarroo Parade into Bass Point Reserve. Park in the Bass Point Reserve car park. The cave's exact location is not published; it is visited on guided dives by Shellharbour Scuba and Photography Centre, whose guides know the entry point and route.

Boat access from Shellharbour Marina is also possible.

The northern (Shellharbour-facing) side of Bass Point is protected from southerly winds and swell – even gale-force southerlies – which makes it the Illawarra's reliable shore-diving fallback. It is blown out by north-east swell over about 1 m and by strong nor'easters, which are common on summer afternoons, so summer dives are best done in the morning. Tide is not critical but high tide makes entries and exits over the rock platform easier.

Visibility ranges from 5 m after swell or rain to 15–20 m in winter westerly spells. The reserve gate may be closed on total fire ban days.

Dive with a local guide who knows the cave's location; spend time around the overhang for blue devils, then search the surrounding algae and turf slowly for pygmy pipehorses.

Shellharbour Scuba and Photography Centre includes it in its Bass Point guided dives, particularly for macro photographers seeking pygmy pipehorses.