U.S. Sailors aboard a riverine command boat (RCB) assigned to Commander Task Group (CTG) 56.7 pass an oil tanker after completing a live-fire exercise in the Persian Gulf Dec. 12, 2013. RCB's provided a multimission platform for the U.S. 5th Fleet area of responsibility by focusing on maritime security operations, maritime infrastructure protection and theater security cooperation efforts, as well as conduct offensive combat operations.