The continental shelf drops away less than four kilometres offshore from Augusta, carving a subsea canyon where the Indian Ocean and Southern Ocean meet. That geological fault line draws northbound humpback whales into Flinders Bay each winter, funnelling a migration route that has run unbroken for millennia. By June, pods of mothers and calves move through the shallows within sight of Cape Leeuwin lighthouse, close enough that researchers catalogue individual flukes from shore. The augusta whale watching eco tour operates from Augusta Boat Harbour year-round, though sightings peak between June and September when humpback numbers swell into the thousands. Flinders Bay was a whaling station until 1978, its shore-based operations processing over two thousand whales across four decades. The last harpoon platform still stands at the eastern headland, rusted silent. Within a generation, the same waters became a sanctuary zone, and the population rebounded at eight percent annually. Today's charter vessels move under strict approach protocols—no closer than fifty metres to adults, one hundred to calves—enforced by federal marine parks legislation. Whale numbers along the Leeuwin-Naturaliste corridor now exceed thirty-five thousand during the migration window, one of the densest concentrations in Australian waters. Naturaliste Charters runs daily departures at 10am and 2pm from Leeuwin Road harbour, with hydrophones lowered mid-voyage to catch humpback song beneath the hull. The route follows the shelf break southwest toward the cape, where upwelling currents bring nutrient-rich water to the surface. Breaching behaviour intensifies in the bay's calmer northern quadrant, sheltered from the prevailing westerlies. Pods linger for hours in water shallow enough to rest, calves testing their lungs in repeated surface rolls. Marine biologists ride select charters to record fluke markings and catalogue matrilineal groups, data pooled into a coast-wide migration study that spans three decades. The eco tour protocol includes a no-touch policy and engine shutdown during close encounters, minimising acoustic disturbance while the whales surface and breathe.