Blue's Canyon is a long, narrow cleft in the granite of Breaksea Island's south-western corner – about 300 m long and only 5-6 m wide – that runs from 9 m at its head to about 45 m where it opens out. Marine Life Network describes its walls as covered in sponges, with cowry shells and crayfish in the cracks, resident wobbegong sharks on the floor and very large blue groper and queen snapper patrolling the canyon.

The dive has an unusual intimacy for an ocean-facing site: the walls are close on both sides, so divers swim through a corridor of sponge colour, looking up at a strip of light. The crayfish (southern rock lobster) are protected from fishers in the confined space and sit openly in the cracks, and the wobbegongs lie on ledges and on the canyon floor. The groper and queen snapper are among the largest seen around Albany.

Because the canyon descends continuously, it rewards careful depth management. Recreational divers generally turn at 25-30 m, which still covers the most colourful part; the deeper section toward 45 m is for experienced deep or technical divers. The main constraint, though, is swell: the site faces the ocean, and even moderate swell sends surge funnelling through the canyon.

When the weather allows, Blue's Canyon is widely considered one of the best dives in the Albany area – a genuine temperate-reef spectacle for experienced divers. The dive shop chooses it opportunistically on flat days, so ask in advance if it is on your list.

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. Breaksea Island lies across the entrance of King George Sound, about 9-10 km south-east of Emu Point (20-25 minutes by boat in good conditions, longer from the town ramp).

Blue's Canyon is on the south-west corner of Breaksea Island, which faces the ocean, so boats only go there on minimal-swell days. Divers are dropped at the canyon head and the boat stays live or anchors in sand nearby.

The south-west corner of Breaksea faces the Southern Ocean, so Blue's Canyon is only dived on days of minimal swell – realistically under 1 m – with light winds. Any south-westerly swell creates heavy surge in the narrow canyon, and south-westerly winds make the site dangerous. Late summer and autumn high-pressure systems provide the best windows.

Visibility is often excellent when it is diveable.

Drop in at the canyon head at about 9-12 m and follow the canyon floor downslope, keeping to a planned maximum depth (typically 25-30 m for recreational divers). Turn at the planned depth or pressure, return up the canyon along the opposite wall, and finish with a safety stop in the shallows at the head.

Continuous descending profile – set a hard turn depth. Beyond 40 m requires deep/technical training.

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 on flat days; Perth Scuba's Albany weekends list 'Bluey's Canyon' among their sites.