United States submarines are military vessels designed to operate underwater. They play a crucial role in naval warfare, intelligence gathering, and strategic deterrence. The U.S. Navy operates various classes of submarines, including nuclear-powered submarines and diesel-electric submarines, each serving different purposes. These submarines can carry out a range of missions, such as surveillance, reconnaissance, and launching ballistic missiles. The most advanced class, the Virginia-class, features cutting-edge technology for stealth and combat capabilities. Overall, U.S. submarines are vital assets in maintaining national security and maritime dominance.