Fenwick Bight is the shallow, south-facing indentation between South Point and the cliffs running east towards South East Point, named for Frederick Fenwick, an early settler. Scuba Doctor lists it as a 10–30 m reef dive for Advanced divers and describes a fringe of granite boulders along the shoreline, ending in sand in moderate depths, with the eastern end offering shelter in good weather and the deeper areas towards the point showing vertical walls and small caves. It is a transitional site: the eastern boulders are a relaxed dive over kelp-topped granite with ledges and gutters, while the western end, closer to South Point, steepens into walls and cave-like overhangs where the current and swell have stripped the kelp and encouraged sponge, zoanthid and ascidian growth.

The fish list is the southern Prom standard – barber perch in clouds, boarfish, leatherjackets, sea carp (marblefish) grazing in the shallows and wrasse everywhere – and crayfish sit in the ledges, protected here as everywhere in the marine national park. Fur seals from the Anser Group pass through. Visibility is usually good but the bight collects swell and can be surgy at the boulder fringe.

Fenwick Bight is the natural second dive for a boat that has done South Point or the Anser Islands, providing a less current-affected alternative with a sheltered anchorage at its eastern end when the wind is from the west; it is very rarely dived otherwise, being as far from any launch as anything on the Prom. Divers who reach it will find a quiet, scenic boulder reef at the southern extremity of the mainland, with the walls near the point giving a taste of the bigger topography further out.

Boat only. The nearest launch is the Tidal River beach ramp at the western end of Norman Bay (4WD beach launch, key and deposit from the Parks Victoria office; needs several people and calm surf), from which the western islands are 5–12 km. Larger trailer boats launch at Port Welshpool (sealed ramp, Corner Inlet) and run about 50–60 km around South East Point – 1.5–2 hours – or at Sandy Point (Waratah Bay, beach ramp) and run 35–45 km south-east.

Sites are exposed to Bass Strait and require settled weather, a seaworthy boat, radio, and self-sufficiency: there is no rescue or refuelling closer than Port Welshpool. Fenwick Bight is 1.3 km east of South Point – about 12 km from Tidal River or 43 km from Port Welshpool around South East Point. The eastern end of the bight gives some shelter in good weather; anchor in sand off the boulder fringe.

Faces south into often turbulent Bass Strait water and remains exposed to southerly and south-westerly winds even at its sheltered eastern end. Best dived at slack water with calm seas, minimal swell and no wind; light offshore south-westerly to westerly winds acceptable, moderate to strong onshore south-easterly to south-westerly winds not. Autumn calms are the realistic window.

Anchor in sand at 15–20 m off the boulder fringe at the eastern end, descend and follow the boulders west towards the point, where the vertical walls and small caves begin, dropping to a maximum of 30 m. Turn at half gas or when current builds towards South Point, and return along the boulder line at 10–15 m to the anchor.

No dive charter operates at Wilsons Promontory. Sites are dived from club and private trailer boats – Dive La Trobe, VSAG, Melbourne University Underwater Club and Dive Victoria Group run occasional camping-and-diving trips – launching at Tidal River (beach launch, permit/key from Parks Victoria), Port Welshpool or Sandy Point. Wilsons Promontory Cruises (Port Welshpool) runs sightseeing cruises to Skull Rock and the islands but no diving.