Arthurs Peak rises above the coast south-east of Port Arthur, and in the bay near Budget Head its cliffs drop to a reef of large boulders. The Marine Life Network guide lists the site at 15-25 m, with large boulders, patches of delicate marine life, banded morwong and schooling fish. The depth means the boulders are below the worst of the surge that affects the shallower cliff-base reefs on this coast, so more delicate invertebrates such as sponges, hydroids and small anemones survive in the sheltered faces.

Banded morwong rest on the boulders, schools of fish such as butterfly perch or bastard trumpeter pass by, and rock lobsters are likely in the deeper cavities. The site is rarely visited and has little recent documentation, making it an exploratory dive for private boat owners based at Port Arthur or Nubeena. It suits divers comfortable at 20-25 m in cold water.

As with other sites on this stretch, southerly swell is the main constraint. The approach from Port Arthur passes the historic penitentiary and the Isle of the Dead, and fur seals, dolphins and albatross are often seen on the way out. Because the site is seldom dived, fish are relatively unwary and big banded morwong allow a close approach.

Take a torch to look into the deeper gaps between the boulders, where colour is richest. Divers without their own boat can ask Go Dive Tasmania whether Port Arthur-side sites are planned when they launch from Port Arthur, or combine a visit with shore dives at Safety Cove and Frying Pan Point, which require no boat at all.

Boat access only. Launch at the Port Arthur boat ramp (Carnarvon Bay, off Safety Cove Road) or at Nubeena and head south-east out of Port Arthur towards Budget Head, about 15-20 minutes. Anchor in sand clear of the boulders or run a live boat under the cliffs.

There is no shore access. The Port Arthur ramp has trailer parking and toilets and is close to the historic site; fuel and supplies are available at Port Arthur and Nubeena.

Faces south into Storm Bay; closed by southerly and south-easterly swell and strong southerly winds. Northerly and westerly winds give calm conditions. Best in late summer and autumn after several days of offshore winds.

Visibility drops after storms as the sand bottom stirs up. Afternoon sea breezes are less of an issue than on the east coast, but south-westerly changes arrive quickly in any season.

Descend to the largest boulders at about 20-25 m, weave between them looking for the delicate invertebrate patches in sheltered spots, then rise to 15 m along the cliff base before ascending.

No regular operator; private boats and club divers from Port Arthur.