Top 5 Great Barrier Reef Dive Sites: Coral Sea & Ribbon ReefsTo experience the Great Barrier Reef’s very best dive sites, bypass the day boats, jump on a liveaboard and head north to the Ribbon Reefs and Coral Sea. Here are five of the best dive sites in the Coral Sea and Ribbon Reefs. Cod Hole, Ribbon Reef 10Located on the northern stretch of the Ribbon Reefs, Cod Hole is possibly the Great Barrier Reef’s bestknown dive site. The Ribbon Reefs are a series of coral reefs on the northern Great Barrier Reef, known for healthy corals, unique marine life, and encounters with minke whales. The Coral Sea and northern Ribbon Reefs are too far for day boats and are best accessed on liveaboard trips from Cairns.