JS Shirane (DDH 143), of the Japanese Self Defense Force, transits the waters of Joint Base Pearl Harbor-Hickam during the biennial Rim of the Pacific (RIMPAC) exercise. Twenty-two nations, 42 ships, six submarines, more than 200 aircraft and 25,000 personnel are participating in RIMPAC from June 29 to Aug. 3, in and around the Hawaiian Islands. The world's largest international international maritime exercise, RIMPAC provides a unique training opportunity that helps participants foster and sustain the cooperative relationships that are critical to ensuring the safety of sea lanes and security on the world's oceans. RIMPAC 2012 is the 23rd exercise in the series that began in 1971.