U.S. and foreign service members attend a safety brief in relation to the Rim of the Pacific (RIMPAC) exercise at the base theater aboard Marine Corps Base Hawaii (MCBH) June 27, 2018. The brief informed exercise participants on the rules, regulations, and requirements for all ranges and training areas aboard MCBH. The brief also provided awareness of the cultural and natural resources related to MCBH. Twenty-five nations, more than 45 ships and submarines, about 200 aircraft, and 25,000 personnel are participating in RIMPAC from June 27 to Aug. 2 in and around the Hawaiian Islands and Southern California. The world's largest international maritime exercise, RIMPAC provides a unique training opportunity while fostering and sustaining cooperative relationships among participants critical to ensuring the safety of sea lanes and security on the world's oceans.