The former HMAS Perth is Western Australia's largest purpose-scuttled dive wreck and, for many temperate-water divers, the best reason to drive to Albany. She was a Charles F. Adams-class guided-missile destroyer built by Defoe Shipbuilding in Bay City, Michigan, laid down in 1962 and commissioned into the Royal Australian Navy in July 1965. Perth made three deployments to the Vietnam War between 1967 and 1971, firing more than 30,000 five-inch rounds on the gunline and coming under fire from coastal batteries several times; some of that shell damage can still be picked out on the hull. After 34 years of service she was decommissioned in October 1999, gifted to the Western Australian government and scuttled on 24 November 2001 about 500 m south-west of Seal Island in King George Sound.

The ship sits upright on a sand bottom at about 35 m. She is 133 m long and was sunk with far more of her fittings left in place than the earlier HMAS Swan at Dunsborough: the bridge and captain's chair, radar and mast, the forward gun mount, heads and galley areas remain, and the engine room was prepared with full access. The mast was originally left breaking the surface. An interpretive dive trail with plaques leads around the hull, and the local dive shop sells slates showing suggested routes. Most of the superstructure lies between about 10 and 20 m, the main deck around 25 m and the sand at 34-35 m, so a single dive rarely covers the whole ship.

Two decades underwater have produced dense sponge, ascidian, soft-coral and mussel growth over the hull, and the wreck holds schools of yellowtail scad and old wives along with big yellowtail kingfish, samson fish and jewfish, cuttlefish, wobbegong and other carpet sharks. Visibility is modest compared with the outer islands, but on a clear day the scale of the ship is striking. It suits Advanced Open Water divers for the exterior; penetration of the interior, especially the engine room, is for wreck-trained divers only.

Albany is 418 km (about 4.5 hours) south-east of Perth via Albany Highway. Charter boats and private boats launch either from the Emu Point boat ramp (Emu Point Drive, 7 km north-east of the CBD, with a large trailer car park, toilets and a fish-cleaning station) or from the town ramp beside the Albany Waterfront marina in Princess Royal Harbour, which exits into King George Sound through the harbour entrance past Possession Point. The Perth is about 8 km (15-20 minutes) from the Princess Royal Harbour ramp and slightly further from Emu Point.

The site has public mooring buoys attached to the wreck; divers on private boats must tie to a mooring rather than anchor into the hull. Most visiting divers go with South Coast Diving Supplies, which departs from the town waterfront. A permit is required for private-boat diving and is bought cheaply over the counter at the dive shop.

King George Sound is sheltered from the Southern Ocean by Flinders Peninsula, Bald Head and Breaksea and Michaelmas Islands, which is why Albany can offer diving on days when the open coast is wild. The Perth is well protected from southerly and south-westerly ocean swell and is one of the few sites around Albany that is diveable in almost any season. Strong easterly and north-easterly winds put a chop across the sound that makes the moorings uncomfortable, and strong westerlies make the run out from the harbour wet.

There is generally no current on the wreck. Visibility is the main variable: it is often under 10 m and drops after winter rain when run-off from Oyster Harbour and Princess Royal Harbour spreads into the sound; the clearest water is usually in late summer and autumn after a run of settled weather.

Descend a bow or stern mooring line to the upper superstructure at 10-15 m and let the first dive be an orientation along the length of the ship on the main deck (about 25-28 m), visiting the forward 5-inch gun mount, the bridge and the missile launcher area before returning along the other side. Keep an eye on no-decompression limits because the deck is deep enough to eat bottom time quickly. Finish by working up the mast and superstructure, and do the safety stop on the mooring line.

Nitrox (EAN28-32) extends bottom time usefully on the deck. Interior penetration, particularly the engine room, should only be done with wreck training, a guideline and redundant light; silt disturbs quickly. The wreck was prepared for divers (hatches removed, hazardous material stripped) but has been underwater since 2001 and fittings are deteriorating.

South Coast Diving Supplies (Albany) – the town's dive shop; runs scheduled boat dives in King George Sound most weekends and on demand in summer/autumn, and issues HMAS Perth permits; Perth Scuba (Perth) – runs scheduled Albany dive weekends that include the Perth, Cheynes III and Breaksea sites; Perth-based clubs run occasional trips.