Kaneohe Bay, bay on the northeastern shore of Oahu island, Hawaii, U.S. A major tourist destination, it contains clear, shallow waters and vivid underwater coral formations that can be viewed from glass-bottom boats. Extending between Kaneohe Beach Park (south) and Kualoa Point (north), its 20-mile (32-km) shoreline is rimmed with ancient royal fishponds, including Waikalua Loko. The Hawaii Institute of Marine Biology of the University of Hawaii is on Moku O Loe (also called Coconut Island) in the bay. Moku Manu (“Bird Island”), 1 mile (1.6 km) north of Mokapu Point, is a twin-isle refuge for terns and man-o’-war birds that lead fishermen to schools of ocean fish. Mokapu Peninsula, jutting into the bay to form an eastern shore, is the site of a U.S. Marine Corps base. The primary settlement along the bay is Kaneohe.