Pro Dive groups Gower Pinnacle and The Triangle together as a pair of deep sites off the southern end of the island. Its description is of a plateau starting at 20 m, an escarpment, a platform at about 32 m and rocky canyons past 40 m. It is one of the deepest regular dives at Lord Howe and one of the most exposed.

The attraction is big fish. Pro Dive's dive account records sharks, a school of about 30 spangled emperor and three huge kingfish, estimated at five to six feet, that followed the divers throughout the dive. Kingfish grow large at Lord Howe because the island has been protected for decades, and the southern pinnacles, where the current runs past Mt Gower, are where they gather.

The reef itself carries black coral trees on the escarpment and holds two of the most sought-after angelfish in the region: the Meredith's angelfish and the conspicuous angelfish, both subtropical species with restricted ranges. High-fin coralfish are also recorded. Divers who enjoy fish-watching will find this one of the richest sites on the island.

This is a deep dive and requires deep training and experience. The plateau at 20 m is a good depth for those who want to stay shallower, while the platform at 32 m and the canyons below are for divers with the right certification and gas planning. The southern end of the island is exposed to the south-east trades and southerly swell, so trips here are made only on calm days, and the run is longer than for most sites. Coordinates are approximate.

Lord Howe is reached only by air: QantasLink flies from Sydney daily (about 1 h 50 min), with Brisbane and seasonal Port Macquarie services. Accommodation must be booked before flights (visitor numbers are capped at about 400) and the checked-baggage limit is 14 kg, so most divers hire gear on the island. Dive Lord Howe's shop is at 2 Lagoon Road beside the Lagoon Beach boatsheds; most lodges transfer divers or it is a short bike ride.

Divers board the boat, which is moored in the lagoon, and leave the lagoon through Erscott's Passage at its southern end, then run south along the western coast beneath Mt Lidgbird and Mt Gower. The southern sites are the longest runs of the regular dives, roughly 25–30 minutes, and are done only when the sea allows.

Lord Howe sits in the path of the prevailing south-east to east trades and winter westerly fronts. The southern end of the island below Mt Gower is fully exposed to the south-east trades and to southerly and south-westerly swell, which is why the southern sites are dived only on calm days or in northerly to north-easterly winds. More than about 1.5 m of southerly swell or 15 knots of south-easterly closes them.

Current can run around Gower Island and the pinnacles. February–May usually brings the most suitable days; winter trips are uncommon.

Descend the line to the plateau at about 20 m and follow the escarpment down to the 32 m platform, watching the blue for kingfish and schools of spangled emperor. Only divers with deep training should drop into the canyons past 40 m. Ascend along the escarpment and finish the safety stop on the line.

Nitrox useful on the plateau; the canyons past 40 m exceed recreational limits and require technical training and gas planning.

Dive Lord Howe (PADI 5-star, 2 Lagoon Road) – morning double boat dives daily in season, afternoon single dives on demand; site chosen on the day by wind and swell. Howea Divers has also advertised dives here.