Poseidon s high cruising speed takes you to the VERY OUTER EDGE of the Great Barrier Reef for superb snorkelling and diving on the completely unspoilt Agincourt Ribbon Reefs. Owned and operated by a local Port Douglas family Poseidon has always strived for excellence in customer service and offers the discerning visitor a true five-star reef experience. They are proud to offer a high crew:passenger ratio with dedicated snorkeling crew and dive instructors offering in-water assistance for beginners.