The Bay of Islands is one of the best places in the country to see common and bottlenose dolphins in the wild. Both species are resident year-round in the inner bay and frequently approach the tour boats running between Paihia, Russell and the outer islands.
Swimming with the dolphins, once a major drawcard, has been progressively restricted by the Department of Conservation since 2019 to reduce stress on the bottlenose population, whose numbers have declined sharply. Boat-based viewing is still permitted and several operators offer dolphin-spotting trips, often combined with the Hole in the Rock cruise. Whale sightings — usually Bryde's whales or orca — are occasional bonuses, especially in winter.