Little Boat Harbour is the dive that has made Bremer Bay a destination. This small, sheltered cove on Dillon Bay holds a marked dive trail through kelp forest, granite outcrops and sand patches in no more than about 10 m, and it is one of the most reliable places in Australia to see leafy seadragons – along with weedy seadragons – in the wild. Bremer Bay Dive, which has operated in the town since 1994, runs guided seadragon dives here most mornings; its owner has spent years researching seadragons and their conservation in the area, and guides can often go straight to known individuals.

The habitat is classic southern temperate: Ecklonia kelp and sargassum on the rocks, seagrass and sand in the gaps, and granite boulders with sponges, sausage corals, tube worms and basket stars. Leafy seadragons drift at the kelp margins, their camouflage making them easy to overlook, while weedies feed over the sand edges. The supporting cast includes cuttlefish, squid, octopus, stingrays, neon nudibranchs and other nudibranchs, morwong, harlequin fish, western blue devils and damselfish, with occasional seals and dolphins.

Because the depth is shallow and the entry easy, the site suits divers of all levels and free divers, and it is an outstanding macro and wide-angle photography location. The key is patience: swim slowly, look along the kelp edge, and avoid touching or chasing the dragons, which are protected under WA law.

Bremer Bay is a long way from anywhere – two hours past Albany – and the diving is weather-dependent, but for many temperate-water divers seeing a leafy seadragon here is reason enough for the drive. Combine it with the bay's other sites and, from December to April, an orca expedition to the Bremer Canyon.

Bremer Bay is about 180 km (2 hours) north-east of Albany and 500 km (5-6 hours) south-east of Perth via the Albany Highway and Borden-Bremer Bay Road, or via the South Coast Highway and Bremer Bay Road. Air fills, hire gear and guided dives are available from Bremer Bay Dive in town. From the township drive south toward the Bremer Bay boat harbour and follow the signs to Little Boat Harbour on Dillon Bay (about 10 minutes); the road is accessible to 2WD vehicles.

Park above the small beach and carry gear a short distance to the sand. The trail starts from the beach. Bremer Bay Dive guides meet divers at the shop at 8 am and drive to the site.

Little Boat Harbour faces east into Dillon Bay and is sheltered from the prevailing south-westerly swell. Bremer Bay Dive notes that with headlands facing different directions there is usually somewhere diveable in most weather; this site is the westerly and south-westerly-weather choice. Strong easterly and south-easterly winds (common summer afternoon sea breezes) create chop and surge and stir up sand, so dive in the morning.

Winter storms can reduce visibility for several days.

Enter from the beach and follow the dive trail markers out along the kelp and granite edge to 6-10 m, searching the kelp margins and sand patches slowly for seadragons. Guides typically spend most of the dive with individual dragons. Return along the shallower rocks to the beach.

Bremer Bay Dive – local dive shop (operating since 1994) running guided seadragon shore dives most mornings at 8 am in suitable weather, scooter dives and gear hire – the trail is its signature guided dive; guides know individual seadragons.