The mission of the reconnaissance battalions is to obtain information by visual observation about the activities and resources of an enemy or potential enemy, or about the meteorologic, hydrographic, or geographic characteristics of a particular area. They specialize in amphibious recon, including hydrography; as well as airborne recon, infiltration via surface, subsurface and airborne operations, and conducting limited scale raids and ambushes. The battalions consist of a headquarters and service company and one to four reconnaissance companies (divisional assets, individual companies usually attached to an RCT). All battalions (except 4th Recon) also have a force reconnaissance company dedicated to provide deep reconnaissance and direct action capability to a MEF HQ. (Two additional separate force reconnaissance companies exist in the Marine Forces Reserve.)