U.S. Marines with 3d Marine Littoral Regiment, 3rd Marine Division, execute Exercise Spartan Trident at Marine Corps Base Hawaii, Sept. 29, 2022. Spartan Trident is a three-part exercise designed to facilitate the development and refinement of tactics, techniques, and procedures required to serve as the inaugural Marine Littoral Regiment. - U.S. Marines with 3d Marine Littoral Regiment, 3rd Marine Division, execute Exercise Spartan Trident at Marine Corps Base Hawaii, Sept. 29, 2022. Spartan Trident is a three-part exercise designed to facilitate the development and refinement of tactics, techniques, and procedures required to serve as the inaugural Marine Littoral Regiment.