Naval Mobile Construction Battalion 25 or NMCB 25 is a Navy Reserve Seabee unit that is headquartered at Port Hueneme, CA. Its World War II predecessor was one of three CBs transferred to the Marine Corps in the late summer of 1942 as combat engineers. Those three battalions were attached to composite Marine Engineer Regiments as the third battalion of their respective regiment. All of them remained with the Marine Corps for the next two years before they were released and returned to the Navy. At the end of World War II the battalion was decommissioned. In 1961, it was recommissioned in the Naval Construction Force Reserve where it remains today.