Bunbury's Outer Harbour breakwaters provide rocky habitat in otherwise sandy northern Geographe Bay. A regional holiday guide lists the Outer Harbour as a snorkel and dive site with rocky reefs, seagrass beds and sandy bottoms, and a wide range of life including bream, whiting, herring, sea stars, anemones, nudibranchs, rays and cuttlefish, suitable for all levels.

Like harbour walls elsewhere, the boulders of the breakwater create crevices for fish and invertebrates, and the seagrass and sand around them add rays, cuttlefish and small critters. It is a macro and fish-watching dive rather than a scenic one, with modest visibility.

Access needs care. The Outer Harbour is a working port, with shipping, tugs and restricted zones, and access arrangements can change; divers should confirm where diving is permitted before entering and stay well clear of berths and channels. Fishing from the breakwater is common, so expect lines and hooks.

The site suits local divers wanting a quick shore dive with critters, and is best on calm days with light winds.

Geographe Bay is unusual on the WA coast because it faces north, so the prevailing south-westerly swell and sea breeze that close the ocean coast are largely blocked by Cape Naturaliste. That shelter, plus the warm Leeuwin Current, is what makes the bay's reefs, jetties and wrecks diveable for much of the year, and why winter north-westerly storms are the main thing that shuts it down.

The Outer Harbour lies on the northern side of the Bunbury peninsula. Access points and permitted areas change with port operations, so check current Southern Ports access rules before diving; park at the public foreshore areas and enter from sand beside the rock wall on the sheltered side. Avoid navigation channels and port berths.

Bunbury has a local dive shop (Coastal Water Dive) for fills and hire.

The breakwater's inner side is sheltered from the south-west swell; the outer side is exposed. Strong northerly winds reduce visibility. Visibility is often limited by harbour sediment and after rain.

General pattern in Geographe Bay: sheltered from south-westerly swell by Cape Naturaliste; summer mornings are calm before the afternoon sea breeze, while winter north-westerly fronts roll swell and chop into the bay and reduce visibility for several days.

Enter from sand on the sheltered side, follow the base of the rock wall at 3-6 m looking into the boulders, then return the same way; stay out of shipping channels. Agree a turn pressure before descending (half gas, or a third where current is likely), carry a DSMB, and make a 3-minute safety stop at 5 m.

No regular operator; local divers only. Ask Bunbury dive shops about current access. Nearest dive services: Octopus Garden Dive Charters and Coastal Water Dive in Bunbury; Swan Dive in Busselton.