SWA OWS Series: Koombana Bay

The water here is shallow, a vast sandy basin that keeps the Indian Ocean's more aggressive swells at bay. As you pull through the calm, protected stretch of Koombana Bay, your hand might break the surface just as a dorsal fin surfaces nearby; the resident wild bottlenose dolphins are a constant presence in these waters, often observed near the local research facility. This is the stage for the SWA OWS Series: Koombana Bay, a key event in Western Australia’s open water calendar, held annually in January.

Historical currents

History here is etched into the coastline. Looking toward the shore, you are retracing the route of Captain Louis de Freycinet, who charted this inlet in 1803 from the deck of the Casuarina. His legacy survives in the names of the surrounding features, though the area soon transitioned into a hub for the whaling industry, which drove European expansion between the 1830s and 1850s. The seabed itself holds more modern, man-made history, including the remnants of vessels like the HMAS Swan, which lies as an artificial reef in the deeper waters of the adjacent Geographe Bay, a destination for those who prefer their maritime exploration with a tank on their back.

A port in flux

Swimming these lines, you are crossing a site of intense industrial and political friction. On 19 July 1976, the quiet of this bay was shattered when over 1,000 sticks of gelignite were detonated at the woodchip terminal, a blast that resonated for 20 kilometres and permanently altered the port’s infrastructure. Today, the water is reclaimed by the rhythm of the tides and the race itself. The event offers distances from 500m up to the 10km marathon, catering to varied skill sets. The shallow nature of the bay, which once restricted the entry of deep-draft ships, provides a unique, sheltered environment for long-distance swimming, shielded by the natural breakwater of Cape Naturaliste. The race schedule demands precision, as the local currents are dictated by the specific tidal flow of the inlet, requiring swimmers to time their effort to the shifting water levels.