NATO Maritime Command (MARCOM) is the central command of all NATO maritime forces and the Commander MARCOM is the prime maritime advisor to the Alliance. Like its land and air counterparts (LANDCOM & AIRCOM), MARCOM answers directly to NATO's Allied Command Operations (ACO) which is located in Mons, Belgium. Located in Northwood, outside London, United Kingdom, it is composed of a multinational headquarters manned by 300 officers, petty officers and civilians from most NATO countries. MARCOM includes three subordinate commands co-located in Northwood for coordination on specific areas of maritime engagement and Allied forces when assigned to NATO. These commands are as follows: Submarines NATO, which directs submarines under NATO operational control; Maritime Air NATO, which directs the activities of Maritime Patrol Aircraft under NATO operational control; and the NATO Shipping Centre, which is a direct liaison with the wider commercial shipping community. MARCOM also leads four Standing Maritime Groups which are a multinational, integrated maritime force made up of vessels from various allied countries. These vessels are continuously available to NATO to perform different tasks ranging from participating in exercises to conducting operational missions. These groups provide NATO with a continuous maritime capability for operations and other activities in peacetime and in periods of crisis and conflict. They also help to establish Alliance presence, demonstrate solidarity, conduct visits to different countries, support transformation and provide a variety of maritime military capabilities to ongoing missions. The number of ships in each group varies based on the requirements for the group and the availability of Allied Navy ships.Find out more at our website www.mc.nato.int or on Twitter, Facebook or YouTube.