U.S. 5TH FLEET AREA OF OPERATIONS (July 26, 2023) Staff members from the International Maritime Security Construct (IMSC) board a P-8A Poseidon maritime patrol and reconnaissance aircraft in the U.S. 5th Fleet area of operations during exercise Sentinel Shield, July 26, 2023. Sentinel Shield is a recurring exercise series led by the IMSC’s operational arm, Coalition Task Force Sentinel, to enhance communication and coordination between partner naval forces.