Naval Station Norfolk (NSN) is a United States Navy facility located near the mouth of the Elizabeth River and Hampton Roads at Sewells Point in Norfolk. Covering more than 4,300 acres of land, NSN is one of the largest military facilities in the world. The base serves as the deepwater home port for seventy-five warships and submarines, including five of the U.S. Navy's twelve aircraft carriers. It supports numerous naval air squadrons that operate E-2C Hawkeye early warning aircraft, C-2 Greyhound cargo planes, and CH-46 helicopters. The base is also home to many shore-based Naval and joint forces commands with particular emphasis on advance training activities.