Gordons Bay (Thompsons Bay to older divers) is a compact, boat-shed lined inlet between Clovelly and Coogee and home to the Gordons Bay Underwater Nature Trail, a 620 m chain laid on the seabed by the Gordons Bay Scuba Club in the 1980s and anchored with concrete-filled drums, with information plaques at intervals. Following the chain takes you clockwise around the bay: out over the central sand, along the southern reef of scattered rock and a small bombora, to 'The Wall', a short reef face at the head of the sand spit that is the deepest point at about 12 m, then back across the mouth and along the northern side in 6–8 m. The reef is a mix of kelp-covered rock, sponge-encrusted boulders and sand edges, and the fish list from the trail's heyday reads like a Sydney field guide: blue groper, moray eel, mado, old wife, Maori and crimson-banded wrasse, garfish, red morwong, six-spined and velvet leatherjackets, goatfish, eastern foxfish, one-spot pullers, seapike, bullseyes, sergeant baker and silver sweep, with abalone in the rocks.

At night crayfish, sand whiting and baby sharks appear. McFadyen is blunt that the deep part of the bay declined markedly after 1991 – he suspects the chain's galvanic effect or kelp overgrowth smothering the sponges – and that the northern shallows are now the best part of the dive, with bream and luderick in good numbers. That honest assessment matters: this is a beginner and training site and a very good night dive rather than a destination reef.

It sits inside the Bronte–Coogee Aquatic Reserve, so the fish are unafraid, and the trail makes navigation almost impossible to get wrong, which is why every Sydney dive school uses it.

Park at the southern end of the Clovelly Beach car park (or on Cliffbrook Parade/Major Street above the bay) and follow the coastal walkway 200 m south to Gordons Bay; the entry is the natural sloping rock ramp at the western end of the path beside the boat sheds, or the small beach. It is a 5–10 minute walk with gear down steps and an uneven path, so plan the carry. Enter from the ramp when conditions allow, swim out over the sand and pick up the chain of the nature trail.

Exit back at the ramp or beach.

Sheltered from the north and west but open to the south-east: swell above about 1.5 m from the south or east surges into the bay and breaks over the rock ramp, making entry and particularly exit awkward. Visibility is best on the incoming tide and after westerlies; it is poor for a few days after heavy rain because of stormwater. No current.

The boat moorings and dinghies in the bay mean divers should surface close to the trail or the shore. Night dives are excellent – the street lights to the north-west are visible from underwater and help navigation.

From the ramp head south to the sand, pick up the trail chain and follow it clockwise around the bay – out along the southern reef to 'The Wall' at the head of the sand spit (12 m), across the mouth and back along the northern side in 6–8 m, where the fish life is best. Allow 45–60 minutes; the shallow northern reef near the entry is the most productive area for a second loop.

Abyss Scuba Diving, Pro Dive Coogee, Dive Centre Bondi and Frog Dive run training dives and guided nature-trail dives here most weeks; heavily used by independent divers and snorkellers.