Cape Pillar is the south-eastern extremity of the Tasman Peninsula and one of the great landscapes of Tasmania, a vertical wall of columnar dolerite rising almost 300 m from the sea, with the blade-like ridge of the Blade at its tip. Across a narrow channel lies Tasman Island and its lighthouse. The Marine Life Network guide's nearby entries – the Port Arthur eastern cliffs towards Cape Pillar and the north-eastern side of Tasman Island – record quick drop-offs, deep-water sponges, currents and sea mammals, confirming the pattern.

Because the cape sits at the junction of Storm Bay and the Tasman Sea, currents can be strong, and the passage to Tasman Island is best left alone unless conditions are slack. It is a site for experienced divers and competent boat crews, reached only on the calmest days. When it works, the water clarity, scale of the cliffs and density of the invertebrate cover rival the best temperate diving anywhere.

Private boat crews should carry a VHF radio, EPIRB and oxygen, file a trip plan and have a fallback site in the lee of Cape Hauy or inside Fortescue Bay if conditions change. The boat ride itself, under cliffs that dwarf the vessel, is one of the most spectacular in Australia, and seals, albatross and dolphins are often seen on the way.

Boat access only. Most trips use the Fortescue Bay boat ramp (Arthur Highway to Taranna, then 12 km of gravel on Fortescue Road; national park pass required), which is the closest launch to Cape Hauy, the Hippolytes, Munro Bight and Cape Pillar. Eaglehawk Dive Centre and Go Dive Tasmania run from Pirates Bay at Eaglehawk Neck (or Port Arthur for Go Dive), adding 20-30 minutes each way.

There are no moorings on these exposed sites; boats drift or hover and run a live-boat pick-up. Carry full safety gear, a VHF radio and oxygen – the nearest help is at Port Arthur or Eaglehawk Neck and the chamber is in Hobart, about 1.5-2 hours away. From Port Arthur the run past Cape Raoul is longer and more exposed; Fortescue Bay is preferred.

These are the most exposed dive sites on the Tasman Peninsula, facing the Southern Ocean and Tasman Sea with no shelter from southerly or easterly weather. Divers interviewed by the ABC said the Hippolytes need no swell and a westerly wind, and that such windows may occur only a handful of times a year; Easter weekend was noted as one. Anything more than about 1-1.5 m of south-easterly to southerly swell, or easterly winds, makes them undiveable.

Currents are strong and unpredictable, particularly around the Needle, Tasman Island passage and Cape Pillar; plan around neap tides and expect to drift. Late summer and autumn (February-May) offer the best chances; operators confirm on the day.

Pick a drop in the lee of the cape at slack water, descend the wall to 25-30 m and drift along it with the current, ascending gradually. Keep well away from the passage between the cape and Tasman Island when current is running.

Drift-style dives with live boat; depth beyond 40 m on the wall requires technical training.

No regular scheduled trips; Go Dive Tasmania and Eaglehawk Dive Centre may visit in exceptional weather; mostly private boats from Fortescue Bay.