Cenderawasih Bay opens north to the Pacific between the Bird's Head of Western New Guinea - the long hammer-headed peninsula that gives the island its distinctive profile - and the mouth of the Mamberamo River, which drains nearly the entire northern flank of the Central Highlands. The bay is large enough to hold an archipelago inside it: the Biak Islands, also called the Schouten Islands or the Geelvink Islands, cluster at the bay's northern end, with Biak itself and its neighbors Supiori, Numfor, and the Padaido chain strewn across shallow reef waters. Yapen runs east-west for 140 kilometers along the southern side. Smaller islands - Mios Num, Rumberpon, Waar, Roon, Kurudu - stud the interior waters. The Wandammen Peninsula thrusts north from the south shore, dividing the bay into two lobes. Four rivers empty directly into it: the Wamma, Tabai, Warenai, and Wapoga.

In 2002, the Indonesian government formalized what had been building in stages since the 1990s: Teluk Cenderawasih National Park, a marine protected area of roughly 1.45 million hectares covering much of the western bay and most of the reef. It is the largest marine national park in Indonesia and one of the largest in Southeast Asia. The park protects coral reefs that run along hundreds of kilometers of coastline, mangroves, seagrass beds, and the waters of islands including Rumberpon, Roon, and Mios Waar. The adjacent Wondiwoi - or Wandammen - Nature Reserve protects an additional 730 square kilometers of forested peninsula. Cenderawasih Bay is biologically part of the Coral Triangle, the richest marine biodiversity region on Earth, and its reefs have been less affected by crown-of-thorns starfish outbreaks and commercial fishing pressure than equivalent reefs in the Philippines or the Solomon Islands.

At the southern end of the bay, near the village of Kwatisore, fishermen set bagan platforms - floating lift-net rigs that target small fish overnight with underwater lights. Whale sharks, the largest fish in the world, learned years ago that these bagan concentrate food for them. The sharks now routinely approach the platforms, opening their two-meter mouths just below the surface, waiting for the fishermen to throw them scraps. The relationship is unique in the world. Kwatisore is one of the few places where whale sharks reliably aggregate year-round rather than seasonally, and the only place where they have formed a stable commensal bond with a specific fishing practice. The fishermen do not harm them. The sharks do not harm the fishermen. Dive operators in the bay now build itineraries around Kwatisore specifically for this encounter, and the whale sharks seem undisturbed by the attention.

The Dutch reached the bay in 1705 when Jacob Weyland sailed through in the frigate De Geelvink, named after a prominent Amsterdam family. The name stuck in European atlases for more than two centuries. But the region's longer political history belonged to the Sultanate of Tidore in the Maluku islands to the west, whose coastal allies in the Bird's Head and along the bay paid periodic tribute in slaves, ambergris, massoy bark, and other forest products. This tributary system was not Dutch colonial in the modern sense - it was a pre-colonial network that existed long before European contact and that the Dutch eventually inherited and formalized. The coastal Biak people, famous as sailors, moved back and forth across these networks for centuries, carrying goods and oral histories between Ternate, Tidore, Seram, and the Papuan coast.

Fly across Cenderawasih Bay in clear morning weather and you see a scale that satellite photographs do not convey. The water runs through every blue a human eye can name - turquoise over reef shallows, cobalt across the deep central basin, emerald in the mangrove sloughs along the Wandammen coast. Biak's white-sand beaches line the north. The green bulk of Yapen stretches east-west through the southern half. Clouds build over the mountain interior but the bay itself often stays clear through midday. The nearest airports to the bay itself are Biak (BIK / WABB) on Biak Island and Nabire (NBX / WABI) on the southern coast, with Manokwari (MKW / WASR) on the bay's northwestern shore. Small aircraft from these bases serve remote villages on the peninsulas and outer islands. Most of the coastline remains inaccessible except by boat, which is another way of saying the bay has kept a great deal of itself to itself.