The waters around Harstad and the Vesterålen archipelago are among the best places in Norway to see whales. Sperm whales feed in the deep trench off the Vesterålen coast year-round, and humpback and minke whales migrate through the area in summer following the herring shoals. Killer whales (orcas) follow the herring into the fjords in autumn and winter — typically November through February — when they are a common sight in the straits near Harstad.
Several operators run whale watching trips from Harstad and nearby Andenes (the main base for sperm whale watching in the Vesterålen). The whale encounters are close and frequent enough to be genuinely impressive — particularly the orca sightings during the herring season, when groups of 20 or more animals can be seen hunting cooperatively in the fjords.