Outer Great Barrier ReefFor the most otherworldly corals and creatures—that is, what makes the Great Barrier Reef “great” besides its sheer size—snorkelers and divers should venture to outer reef sites such as Cod Hole, the Ribbon Reefs, or even further offshore. Wavelength Cruises, one of the few companies considered Advanced Eco-Certified, offers snorkeling trips to St. Crispin Reef, Tongue Reef, and even Opal Reef, whose plate corals, angelfish, grouper, anemones, and giant clams with fuzzy purple flesh have appeared in BBC documentaries. Better yet, book a multiday live-aboard adventure with Mike Ball Dive Expeditions, which might take you photographing reef sharks, discovering the ancient Osprey nautilus, swimming through swirling schools of neon yellow snapper, or—between June and August—the rare opportunity of coming face-to-face with a friendly dwarf minke whale.
These long, thin coral reefs—10 of them in total—offer some of the best scuba diving and snorkeling in the region. On Ribbon Reef 10, the world-famous dive site Cod Hole boasts massive, friendly potato cod that nuzzle divers like Labradors. And at Ribbon Reef 5, a site called Clam Gardens features giant clams that grow up to 1.8 meters (six feet) wide.