Naval Station Mayport is a Navy Ship Base that is the third-largest fleet concentration area in the U.S. Mayport has a busy harbor capable of accommodating 34 ships, and an runway capable of handling any aircraft used by the Department of Defense. Until 2007, it was home to the aircraft carrier , which locals called "Big John". In January 2009, the Navy committed to stationing a nuclear-powered carrier at Mayport when the official "Record of Decision" was signed. The port will require approximately $500 million in facility enhancements to support the larger vessel, which would take several years to complete. The carrier was projected to arrive in 2019; however, an amphibious group was sent before the carrier.