Between May and November each year, more than 35,000 humpback whales navigate the 10,000-kilometre corridor between Antarctic feeding grounds and subtropical breeding waters off Queensland. The mid-point of that journey passes directly through the Solitary Islands Marine Park, where the continental shelf drops from 40 metres to 600 metres within two nautical miles of Coffs Harbour's coast. That abrupt bathymetric edge creates nutrient upwellings that concentrate krill and small fish, turning the corridor into a predictable feeding lane and one of the densest whale migration routes in the Southern Hemisphere. Coffs Harbour whale watching tours depart from the International Marina, a purpose-built facility opened in 2010 to replace the older Jetty strip berthing. The marina sits at the southern fringe of the Solitary Islands Marine Park, a 70-kilometre reserve established in 1991 to protect the convergence zone where tropical and temperate currents meet. That thermal boundary supports 90 hard coral species—the southernmost reef-building corals on Australia's east coast—and draws transient marine megafauna year-round. During peak migration months in June and July, southbound mothers with newborn calves travel at walking pace, often resting in the sheltered bays between Mutton Bird Island and Split Solitary Island. Northbound whales in September and October move faster, breaching and tail-slapping in competitive pods as males vie for mating access. The standard whale watching cruise operates from 08:30 to 17:00 daily throughout the migration window, with departures timed to morning's calmer sea states and the predictable movement of pods along the 100-metre depth contour. Vessels range from 15-metre aluminium cats to larger mono-hulls certified for 50 passengers, all equipped with hydrophones that broadcast baleen song through onboard speakers. Marine scientists from Southern Cross University's National Marine Science Centre accompany select departures, tracking individual whales using fluke photogrammetry and dorsal fin scarring. Data collected from these citizen-science cruises feeds into the East Australian Humpback Population Study, which has documented the species' recovery from fewer than 500 individuals in 1960 to an estimated population exceeding 40,000 today. The Solitary Islands corridor also supports transient pods of bottlenose dolphins, occasional orcas trailing the humpback migration, and seasonal aggregations of manta rays near the Macauleys Headland upwelling zone. Visibility averages 15 metres during winter months, when offshore winds flatten the Tasman Sea and southbound whales linger within 500 metres of the breakwall.