Troubridge Point is the finest natural reef dive on the lower east side of Yorke Peninsula. Below the headland a large limestone reef system runs for a couple of kilometres along the shore, and The Dive Shack describes it as a huge swim-through, bommies, chasms and pinnacles with amazing fish life. The Marine Life Society of SA notes walls up to 8 m high cut by crevices, sitting about 500 m off the cliffs in 5-15 m, with outer sections dropping to 20 m.

Local divers treat it as the natural second dive after the Clan Ranald wreck, which lies just offshore. The reef is protected as part of the Troubridge Hill Aquatic Reserve, established in 1983 around the Clan Ranald, and the protection shows in the fish life and crayfish, which cannot be taken inside the reserve. The walls and overhangs are dressed in gorgonian fans, sponges and colonial ascidians, and the gutters shelter western blue groper, silver drummer, moonlighters, old wives, herring cale, trevally, magpie perch and schools of coralfish, with southern blue devils in the crevices and cuttlefish on the ledges.

Crayfish are plentiful in the deeper cracks. The character of the dive is classic southern temperate reef: kelp and brown algae on top, invertebrate colour on the vertical faces, and a maze of gutters that rewards slow exploration. It is more exposed than Edithburgh and suffers from surge and poor visibility when southerly swell is running, so it is a calm-weather site.

When conditions line up, though, visibility of 15 m and the combination of topography and fish make it one of the best reef dives within reach of Adelaide by road. It suits divers with some experience of open-coast reef diving; the shore option in particular requires fitness and good judgement of the sea.

Boat is the practical way in: launch at the Edithburgh ramp and run south-west along the coast for about 20-30 minutes to Troubridge Point; the Clan Ranald wreck lies just to the south, so the two are usually dived together. Shore access is via the Troubridge Hill/Troubridge Point road off the Edithburgh–Yorketown coast road, with parking near the clifftop anchor memorial, but the descent to the water is steep and rocky and the best reef is some distance offshore, so shore diving is only for experienced divers in calm, low-swell conditions.

Troubridge Point and the reefs south-west of Edithburgh face Investigator Strait and pick up southerly and south-westerly swell that wraps in from the Southern Ocean past Kangaroo Island. Anything over about 1-1.5 m of southerly swell produces heavy surge on the drop-off and poor visibility, and strong south-westerly winds make the boat run from Edithburgh rough. The best days follow a few days of northerly or light north-westerly winds, which flatten the sea along this coast; February-April with a prevailing northerly is the classic window.

Tidal streams in the strait can run strongly on spring tides, so plan around neaps or the turn of the tide.

From the boat drop onto the reef edge about 500 m off the cliffs, follow the 8 m walls along the reef, weaving through the gutters and the large swim-through, then cross to the outer bommies and pinnacles at 15-20 m before working back up to the reef top to finish with a safety stop over the shallows.

No resident charter; dived by Adelaide shops and clubs on Yorke Peninsula boat weekends (e.g. The Dive Shack, Diving Adelaide) and private boats out of Edithburgh, typically as the second dive after the Clan Ranald.