Day boats leave Cairns for the outer Great Barrier Reef, running half-day snorkelling trips to Saxon and Hastings reefs with up to two hours in the water, plus PADI-led intro dives for first-timers. Numbers are capped so the reef doesn't feel crowded, and gear is included. The same Far North Queensland operator is linked with Spirit of Freedom, a liveaboard for multi-day diving further offshore. Private charters are available for groups.