Ramsden Cave is a large sea cave that runs about 60 m into the base of the cliffs on the southern side of Cape Patton, discovered, according to local history, by a farmer named Ramsden who was chasing a lost goat along the shoreline. The entrance is concealed at the foot of the cliff and is nearly blocked by rockfall; inside are two chambers linked by a narrow passage, the floor of the main chamber lying about 12 m above sea level and mostly covered by pools of water left by high tides. Old accounts mention stalactites and stalagmites, and the cave still takes in sea water on big tides. It is really a caving and coasteering objective that happens to be reached most safely with dive gear, and the Scuba Doctor lists it as a dive site for that reason: the approach along the Cape Patton shore reef is a genuine dive through the large gutters and ledges typical of the Great Southern Reef, with abalone, crayfish, sweep, wrasse and thick kelp on the ridges and the scattered iron of the Speculant on the way.

Everything about the visit is demanding. The cliff descent is 75 m of loose ground and the alternative swim is several hundred metres each way along an exposed shore with no exit between Cobble Creek and the cave. The Scuba Doctor's warning is that you need to be strong, fit and very experienced, with careful planning and very calm weather. In return you get one of the most unusual outings on the Victorian coast: a swim through wild reef under towering cliffs, ending in a dark cavern that very few people have seen. Bring a torch that works underwater and, as the site guide suggests, an inflatable mat helps with exploring the flooded chambers. It suits experienced adventurers rather than divers looking for marine life, and it should never be attempted alone or without leaving a plan with someone on shore.

Cape Patton Lookout is on the Great Ocean Road about 25 km north-east of Apollo Bay. The cave is at the base of the 75 m cliff; the descent starts roughly 200 m west of the lookout above the Speculant wreck and is steep, loose and only for the fit and experienced in dry weather. Most divers instead park at Orchard Creek a little further west, enter from the rock platforms beside Cobble Creek and swim east along the shore reef past the Speculant to the cave entrance, which is hidden at the cliff base and almost blocked by fallen rock.

Allow a long day, tell someone your plan, and carry a waterproof torch; there is no boat access short of a long run from Apollo Bay harbour.

Requires the same perfect day as the Speculant: no swell, light offshore north-westerly wind and a stable forecast, because the cliff base is in the wash zone and the cave takes water on high tides and in any sea. Southerly and south-westerly swell of even half a metre makes the shoreline and the cave mouth dangerous. Time the visit for a falling tide toward low water so the cave floor pools are accessible and you are not caught inside by a rising sea; the floor sits around 12 m above sea level but the entrance is at water level.

Visibility on the swim is usually a few metres. A handful of days a year.

From Cobble Creek swim east along the shore reef in 3–6 m past the Speculant wreckage to the cave mouth, working the gutters and ledges on the way. Surface at the entrance, remove fins if landing inside and explore the two chambers on foot with torches, keeping a close eye on the sea state. Return the same way with at least half your gas, treating the return swim as the main event.

Not a scuba cave – the chambers are above water and explored on foot; no cave certification applies, but coasteering/caving judgement, torches and a surface plan are essential.

No operator – occasional visits by very experienced local shore divers and cavers.