Breaksea Island sits across the eastern entrance to King George Sound, its lighthouse and old keepers' cottages a landmark for every vessel entering Albany. Underwater it offers the widest variety of reef diving in the Albany area, and because the island has sheltered and exposed sides, there is usually somewhere diveable when the wind is not too strong.

Marine Life Network describes several distinct sites. Breaksea Cove, on the south-west corner, runs from 5 to 28 m with plate corals, colourful small fish and caves and overhangs full of invertebrates; it is the easterly-weather choice. On the northern side, west of the landing, Breaksea Boulders is a field of granite blocks in 5-20 m covered with sea fans, sponges and coral plates, with good fish life and often excellent visibility; it is also rated as a fantastic night dive when the weather allows a late trip. The NE side, about 250 m from the eastern end, drops from 2 to 18 m through gutters lined with gorgonian fans and patches of plate coral, with Port Jackson sharks resting on the sand and a seal haul-out where young New Zealand fur seals and Australian sea lions will buzz divers.

The character throughout is big granite – boulders, gutters, caves and swim-throughs – softened by fans, sponges and encrusting corals, and visibility is generally better than inside the sound. Blue groper, harlequin fish, boarfish, western blue devils, queen snapper and schools of sweep and bullseyes are common, with kingfish and samson fish on the outer edges. The island's more advanced sites – The Cables under the lighthouse, Blue's Canyon on the south-west corner and the Southern Dropoff – are described separately. For most visiting divers, a Breaksea double dive is the highlight of an Albany trip after the HMAS Perth.

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).

Site choice depends on wind: Breaksea Cove on the south-west corner is used in easterlies, the Boulders on the northern side west of the landing and the NE side sites in southerly weather. Anchor on sand patches clear of the reef. The island is a nature reserve; landing is by authorisation only.

Breaksea is the outer barrier of King George Sound and takes the Southern Ocean swell on its southern face, so the choice of site is dictated by the weather. Breaksea Cove (SW corner) is fully protected from easterlies but should be avoided in south-westerly winds and southerly swell over about 2 m. The northern Boulders are often very clear but are exposed to strong south-westerly to north-westerly winds.

The NE side is best on calm days, particularly for the caves. The crossing from Emu Point is exposed; if the sound is choppy in a 20-knot wind the outer island trip is usually cancelled.

In Breaksea Cove, descend to 15-20 m and follow the granite along the cove, checking the caves and overhangs, and return shallow over plate corals to the anchor. On the NE side, start 250 m from the eastern end in 10-15 m, explore the fan-lined gutters and sand patches with Port Jackson sharks, and finish in the shallows near the seal haul-out.

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 – Breaksea sites are a staple of its island double-dive trips; Perth Scuba Albany weekends include 'East End of Breaksea'.