Bird Rock off Maria Island (not to be confused with Bird Rock at Bicheno) is an undercut rock with ledges and a cormorant roost, rated 6 out of 10 by the Marine Life Network guide. Depths are only 4-6 m and the rock makes a good anchoring spot.

The ledges shelter banded morwong, leatherjackets and wrasse, with yellow anemones on the rock faces. The guide warns of a shallow reef south of the rock, which is a hazard to boats more than divers.

Bird Rock suits new divers and snorkellers and works well as a relaxed second dive after one of the deeper northern sites such as the North-Eastern Bommie. Keep a respectful distance from roosting cormorants, and do not land on the rock.

Maria Island is a national park with no permanent residents apart from rangers, and the Darlington settlement preserves convict-era buildings from 1825 onwards. The marine reserve along the island's northern and western shores has been no-take since 1991 and has been used for long-term studies of how protection affects rock lobster and fish numbers, so reef life inside it is noticeably richer than outside.

Maria Island's boat sites are rarely visited because there is no operator on the island and the eastern coast is a long way from the Triabunna ramp. Visitors with their own boats should carry oxygen and a radio, check the forecast for Mercury Passage as well as the open coast, and remember that the Royal Hobart Hospital chamber is roughly two hours away by road once back at Triabunna.

Triabunna, on the Tasman Highway 1 hr 15 min (85 km) north-east of Hobart, is the gateway. The Maria Island passenger ferry (Encounter Maria Island) runs several times daily from Triabunna to the Darlington jetty, about 16 km and roughly 30-45 minutes; it carries people and small amounts of luggage but not vehicles, and dive cylinders should be cleared with the operator first. Private boats launch at the Triabunna ramp (best), Saltworks Road ramp, or Orford (shallow bar at the Prosser River mouth - difficult at low tide).

Bird Rock is a good anchoring spot off the northern coast of the island, around 30-35 minutes from Triabunna.

Maria Island's western and northern shores (Darlington, Fossil Cliffs, Painted Cliffs) are sheltered from easterly ocean swell but exposed to strong westerlies and north-westerlies blowing across Mercury Passage, which are common in winter and spring. The eastern side (Mistaken Cape, Bunker Bay) faces the open Tasman Sea and needs westerly weather and small swell. Southerly swell wraps around Cape Peron and the southern end.

Visibility drops after rain as runoff flows from the Prosser River into Mercury Passage. Sheltered in southerly weather; exposed to northerlies.

Anchor near the rock, explore the undercut ledges at 4-6 m and circle the rock, watching for the shallow reef to the south. Turn the dive at half gas (thirds where current or overhead sections are involved), deploy an SMB before surfacing for the live-boat pick-up, and complete a 3-minute safety stop at about 5 m where depth allows.

No operator based on Maria Island. Hobart shops run occasional trips: Go Dive Tasmania has offered Ile des Phoques seal dives and filmed Troy D dives; Tasmanian Scuba Diving Club and Tas Uni Dive Club run club trips from Triabunna. Most diving is from private boats.