Sailing catamarans leave Port Douglas for the northern Great Barrier Reef, trading engine noise for wind on premium snorkelling day trips. Options run from the Outer Reef and Mackay Coral Cay, reached daily and dense with giant clams, rays and turtles, to the coral lagoon at Low Isles, where a marine biologist guides guests over 150 species of hard coral. Afternoon and sunset sails round out the range along the Far North Queensland coast.