OKINAWA, Japan (June 7, 2021) Sailors and Marines from Naval Mobile Construction Battalion (NMCB) 4, Underwater Construction Team (UCT) 2, and 9th Engineer Support Battalion (ESB) discuss plans as the Engineering Reconnaissance Team on Ukibaru Island as part of joint exercise Poseidon's Watchtower. Poseidon's Watchtower is a multi-domain exercise designed to simulate the establishment of Expeditionary Advanced Base operations through joint service integration. (U.S. Navy photo by Builder Constructionman Komlan Adjassem)