Explore australias great barrier reef from the air and the water a scenic helicopter flight or high speed catamaran cruise from port douglas will take you to the outer barrier reef platform on agincourt reef a sheltered base for a day on the great barrier reef explore the reef snorkeling from a semi submersible submarine or from the underwater observatory you can choose to travel by scenic helicopter one way and cruise by high speed catamaran the other or take the helicopter in both direc