Facing the great blue yonder of the Solomon Sea, Milne Bay opens eastwards like the gaping jaws of a giant saltwater crocodile. Located at the southeastern end of the island of New Guinea, at 10°22’00” S latitude and 150°30’00” E longitude, it has a maximum length of 35km, a maximum width of 15km and a surface area of 525km². The bay is surrounded to the north and to the south by the heavily wooded Stirling Range. The narrow coastal strip on the northern shore is soggy, with sago and mangrove swamps.

World War II came to the Australian territory of New Guinea in January 1942 when the Imperial Japanese Army invaded Rabaul in New Britain, followed shortly after by the taking of Kavieng in nearby New Ireland.

The invasion turned New Guinea into a major theatre of war in the battle for the Pacific and there were many brutal encounters between the invading Japanese and the defending Australian forces.

Of all the islands of Papua New Guinea, New Britain is certainly the most active volcanically. Reaching 520km in length and 146km in width, it is the largest island of the Bismarck Archipelago with a total land surface of 36,520 sq km. New Britain’s chains of volcanoes are mostly found along the northern coast, around Rabaul in East New Britain, and along the Willaumez Peninsula, around Kimbe in West New Britain. As a whole, however, the 27 volcanoes are aligned all along the length of the island, from the southwest to the northeast.

It involves a long and usually overnight journey, which will take you down through the St George’s Channel, in-between New Britain and nearby New Ireland. The channel needs to be navigated with respect, as there are some fierce and complex currents flowing through it. It is a journey that Alan Raabe, the skipper and owner of MV FeBrina, has been making regularly for well over 20 years, but only for a few months of each year, during the dry season in the south when pristine underwater visibility returns.

Conditions were often appalling and the fighting was incredibly fierce, with many young lives lost on both sides. To this day, relics of those battles are part of the fabric of Papua New Guinea.

Reef mantas had been known to patrol that beach for many years, but all attempts to try and interact with them were random at best—maybe you would see one or more, maybe you wouldn’t. Then, back in 2002, almost by accident, Craig de Wit discovered why the mantas were there.

Anchored off the east coast in the Bismarck Archipelago, New Britain is home to some of the country’s finest diving. At more than 500km in length, the country’s largest island is home to world-famous Kimbe Bay. Encompassing a huge sweep of the north coast, it is home to 900 fish species and some 70 percent of the coral species found in the entire Indo-Pacific.

Starting from Walindi, I embarked upon a nine-day itinerary that is one of the signature trips of the liveaboard FeBrina, taking in Kimbe Bay, the Witu Islands and Fathers Reefs.

Rabaul’s Simpson Harbour was the Australian Army’s key base in the archipelago, and had to be taken by the Japanese, as they rolled out their plan to seize the main island of Papua New Guinea and isolate Australia to the south. As such, Kavieng also had to be taken, so that the Japanese could protect their rear as they prepared to head west towards Milne Bay.

There can be no doubt regarding the profound fecundity of Kimbe Bay because the numbers, as they say, cannot lie and surveys by some of the best known names in marine biology, such as Professor Charles Veron and Dr Jerry Allen, and respected organizations like The Nature Conservancy, have helped to establish a bewildering array of statistics for the area.