160728-N-SI773-2313 PACIFIC OCEAN (July 28, 2016) Los Angeles-class fast-attack submarine USS Cheyenne (SSN 773), Republic of Korea Chang Bogo-class submarine ROKS Lee Eokgi (SS 071) and Los Angeles-class fast-attack submarine's USS Tucson (SSN 770) and USS Santa Fe (SSN 763) transit in close formation as four of 40 ships and submarines representing 13 international partner nations during Rim of the Pacific 2016. Twenty-six nations, more than 40 ships and submarines, more than 200 aircraft, and 25,000 personnel are participating in RIMPAC from June 30 to Aug. 4, in and around the Hawaiian Islands and Southern California. The world's largest 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 2016 is the 25th exercise in the series that began in 1971. (U.S. Navy Combat Camera photo by Mass Communication Specialist 1st Class Ace Rheaume/Released)