Lady Julia Percy Island (Deen Maar)

Meet the site

Lady Julia Percy Island – Deen Maar to the Gunditjmara, for whom it is a place where the spirits of the dead depart – is a flat-topped volcanic island of about 130 hectares lying 8 km off the coast between Port Fairy and Portland. Its 30–40 m basalt cliffs are undercut with sea caves and drop into boulder reefs and sand in 15–25 m, and around its base lives the largest breeding colony of Australian fur seals in Victoria, several thousand animals that pup in December and are present all year. It is the wildest big-animal dive in the state. The seals, especially the juveniles, are relentless in the water, circling, buzzing and mouthing fins; the basalt walls are coated in sponges, ascidians, bryozoans and hydroids in the colours that cold, upwelled Southern Ocean water produces; crayfish sit in every ledge; and schools of sweep, butterfly perch, boarfish and salmon move along the cliff base. The Scuba Doctor's general mark is on the sheltered western side, chosen from aerial imagery as the most likely lee, and the site guide is candid that the underwater terrain is spectacular all the way round the island and that information on specific spots is thin. The named sites that have been documented – Landing Bay on the north, the Blowhole cave and Leopard Seal Reef on the south – are recorded separately.

Everything about the island is serious. It is a long, exposed crossing from Port Fairy or the difficult Yambuk river entrance; there is no dive charter based nearby, so trips depend on fishing boats or private vessels; the Bonney Upwelling makes the water cold and sometimes green in summer; and great white sharks hunt the colony, most obviously during the summer pupping season. Landing is prohibited without a permit and the wildlife regulations on approaching seals apply. For a well-organised group with a good boat on an autumn high, however, a day at Deen Maar – a wall dive under the cliffs in the morning, a shallow seal dive in the afternoon – is the finest diving in south-west Victoria and comparable to anything in Bass Strait. It suits experienced divers comfortable with big animals, cold water and remote boat operations.

What you might see

Australian fur seals (several thousand, Victoria's largest breeding colony), southern rock lobster, sea sweep, butterfly perch, longsnout boarfish, Australian salmon, blue-throat wrasse, magpie perch, sponges, ascidians and bryozoans on basalt walls, bull kelp, great white sharks (seasonal), little penguins, occasional leopard seals in winter

Location

Flat-topped basalt island 8 km off Yambuk between Port Fairy and Portland, ringed by 30–40 m cliffs, sea caves and boulder reefs, home to Victoria's largest Australian fur seal breeding colony; the Scuba Doctor's general mark is on the sheltered western side.

Facilities nearby

Boat ramps at Port Fairy (Griffiths Street) and Yambuk (Eumeralla River); no facilities on the island; air fills in Warrnambool or Portland.