Bicton Baths is Perth's best-known river macro site and a favourite night dive. The river baths and jetty on the Bicton shore, opposite Point Roe, sit at a narrowing of the Swan where tidal flow brings food to a surprising variety of estuarine animals. Depths run from the shallows to about 15 m further out.

The main attraction is seahorses. Western Australian seahorses are found on the weed, jetty pylons and debris, and the nearby wrecks of the ALC40 and the Gay Dragon are among the most reliable places in the river to see them. Nudibranchs, sea anemones, blennies, porcupinefish, bream, yellowtail grunter, gobies, prawns and crabs are also common, and at night octopus and squid hunt along the bank.

The bottom is fine silty mud that is very easily disturbed, so good buoyancy and a slow pace are essential. Visibility changes with the tide, from about 6 m to under 1 m. Currents are nearly always present and strong away from shore, which is the main reason to stay close to the bank.

Bicton Baths suits Open Water divers, macro photographers and night divers, and it is a good introduction to river diving. It is one of the few Perth sites that can be dived when both the northern and southern coasts are blown out.

River temperatures swing more than the ocean: about 22–26 °C in late summer but as low as 13–15 °C in winter, when a 7 mm suit or drysuit makes a long dive more comfortable. Rinse gear well afterwards, as the estuary water is often high in organic matter.

Bicton Baths are on the Swan River foreshore off Blackwall Reach Parade/Beach Street, Bicton, opposite Point Roe, about 10 minutes from Fremantle. Park in the foreshore car parks and kit up there. Enter from the small beach or the steps beside the baths jetty.

The ALC40 and Gay Dragon wrecks lie a short distance west near the Sea Scouts hall on Jerrat Drive.

Sheltered from ocean swell, so it is diveable in almost any coastal weather. The site sits at a narrowing of the river opposite Point Roe, so slight currents are nearly always present and they are strong away from the shore; neap tides and slack water are best. Visibility varies from about 6 m to under 1 m with the tide and the fine silt.

Heavy rain makes the water colder and darker.

Enter beside the baths, descend in 2–3 m and work slowly along the bank and around the jetty pylons searching for seahorses and nudibranchs, staying within 5–8 m and close to shore. Turn back before the current strengthens further out, and exit at the same point.

Perth dive shops and clubs run occasional guided night and macro dives here; widely dived independently.