Far out into the remote expanse of the Bismarck Sea, north of New Guinea and west of New Britain, we found a hidden treasure: Circular Reef. As National Geographic Orion approached this morning, there was nothing to see above the waves at all. In fact, there were no waves. It was a glassy calm day on this small tropical sea with bright sunshine glinting off the surface, offering perfect conditions for snorkeling. And just under the surface, revealed only by a few low curls of small breakers, we found the spectacular coral walls of Circular Reef. This small atoll is truly a treasure. Uninhabited and very seldomly visited, its walls fall vertically from near the surface to depths of many hundreds of feet and are home to a spectacular variety of reef fish. Swirling over the gorgeous corals were big schools of silver jacks, huge Napoleon wrasses, thousands of brilliantly colored damselfish, small sharks, and much, much more. This remote atoll, concealed beneath the blue waters of the Bismarck Sea, is one of the healthiest reefs I have ever seen, a hidden treasure that we were privileged to visit.