RED SEA (Oct. 25, 2021) The U.S. Navy mine countermeasure ships USS Sentry (MCM 3), left, and USS Gladiator (MCM 11), the guided-missile destroyer USS O'Kane (DDG 77), the amphibious transport dock ship USS Portland (LPD 27) and the Royal Saudi Naval Forces frigate Al Riyadh (812) transit the Red Sea in formation during exercise Indigo Defender 21, Oct. 25, 2021. Indigo Defender 21 is a capstone bilateral maritime exercise between Royal Saudi Naval Forces and U.S. Naval Forces Central Command to enhance interoperability and strengthen our capacity to maintain regional maritime security and stability. (U.S. Marine Corps photo by Sgt. Alexis Flores)