section of the western North Pacific Ocean. Measuring about 170 miles (270 km) east–west, it is bounded by the islands of the Philippines—Mindanao (south and east), Leyte, Bohol, and Cebu (north), and Negros (west). It opens north to the Visayan Sea through Bohol and Tañon straits and the Canigao Channel, east to the Philippine Sea through the Surigao Strait, and west to the Sulu Sea. The sea has rich fishing grounds.