Horn Point is the headland between Sealers Cove and Refuge Cove, named among the Prom's popular dive locations in Parks Victoria's park note and listed by Scuba Doctor at 2–25 m as a safe site suitable for boat diving and shore snorkelling. The dive is a rocky wall descending to a rocky and sandy bottom at 20 m, and the listing's species list marks it out as the eastern Prom's macro and oddity site: large sponges, nudibranchs, sea spiders and basket stars on the wall, morwong, leatherjackets, boxfish, old wives and boarfish over it, and weedy seadragons, southern coralfish and many other novel species occasionally encountered. Basket stars are rare in Victorian recreational depths and sea spiders are easily overlooked, so this is a site to dive slowly with a torch and a macro lens.

The granite wall is broken and ledged rather than sheer, with kelp above and a band of sponges, ascidians and bryozoans below, and the weed line along the sand edge is where the seadragons are found. Southern coralfish – a species more typical of NSW – occur here because the eastern Prom is where the East Australian Current's warm-water strays reach Victoria, and the same reason makes Horn Point a place where unusual fish turn up. It is a boat site from Port Welshpool, most often dived between Sealers Cove and Refuge Cove on an eastern Prom trip, and with the Refuge Cove anchorage 1.3 km away it can be dived from a yacht's dinghy.

It suits Open Water divers in calm conditions and photographers above all; within the marine national park, no take.

Boat only. Launch at Port Welshpool (sealed all-tide ramp, jetty and trailer parking on Corner Inlet, 2.5 hours from Melbourne) and run south through Corner Inlet's marked channels and out past Rabbit Island down the eastern Prom coast – about 30–40 km and 60–90 minutes to Sealers/Refuge Cove, longer to Waterloo Bay and South East Point. The coast is exposed to easterly and southerly swell and has no facilities; carry fuel, radio and all air, and plan around the weather window and Corner Inlet tides.

Horn Point is about 32 km from Port Welshpool, between Sealers and Refuge Coves; anchor in sand off the rocky wall in 12–15 m. The Sealers–Refuge walking track passes over the point and snorkellers with a long walk can reach the shore.

Best with calm seas, minimal swell and no wind; light offshore north-west to south-west winds acceptable, strong onshore north-east to southerly winds not. Autumn calms. The eastern Prom coast is reached only after a long boat run from Port Welshpool, so the whole day's forecast must be settled: swell under 1–1.5 m, light winds, and no change due.

Easterly and south-easterly swell is the main problem on this coast; a westerly wind flattens it but makes Corner Inlet's entrance choppy on the ebb. Visibility is typically 10–25 m and best in autumn after several calm days.

Descend the anchor to the base of the rocky wall at 15–20 m and follow it around the point, examining the large sponges and searching the wall and weed line for seadragons, basket stars and nudibranchs. Turn at half gas, return at 8–12 m along the top of the wall and finish under the boat.

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.