U.S. 5TH FLEET AREA OF RESPONSIBILITY (Dec. 12, 2014) A U.S. Marine with the 1st Combat Engineer Battalion detachment, Battalion Landing Team 2nd Battalion, 1st Marines, 11th Marine Expeditionary Unit (MEU), shows a Saudi Marine how to check for tripwires during a bilateral obstacle breaching exercise as part of exercise Red Reef 15 in the U.S 5th Fleet area of responsibility, Dec. 12, 2014. Red Reef, is part of a routine theater security cooperation engagement plan between the U.S. Navy, U.S. Marine Corps and Royal Saudi Naval Forces that serves as an excellent opportunity to strengthen tactical proficiency in critical mission areas and support long-term regional security.