U.S. Marines with Amphibious Vehicle Test Branch, Marine Corps Tactical Systems Support Activity, test Amphibious Combat Vehicles along the beach during low-light surf transit testing at AVTB Beach on Marine Corps Base Camp Pendleton, California, Dec. 16, 2019. The ACV is a modernized platform providing increased lethality, survivability and protected mobility to Marines. It is designed to fully replace the Corps’ aging fleet of Assault Amphibious Vehicles over the next decade. (U.S. Marine Corps photo by Pfc. Seth G. Merz)