[[File:Virginia class submarine.jpg|thumbnail|300px|center|In the United States, the submarine force is often referred “The Silent Service” because of how it operates. Submarines can submerge more than 600 feet below the ocean's surface for up to four months at a time, constantly patrolling and working classified missions.<ref>[https://www.uso.org/stories/3060-what-you-should-know-about-the-u-s-naval-submarine-force What You Should Know About the U.S. Naval Submarine Force], United Service Organizations (OSO) website</ref> ]] | [[File:Virginia class submarine.jpg|thumbnail|300px|center|In the United States, the submarine force is often referred “The Silent Service” because of how it operates. Submarines can submerge more than 600 feet below the ocean's surface for up to four months at a time, constantly patrolling and working classified missions.<ref>[https://www.uso.org/stories/3060-what-you-should-know-about-the-u-s-naval-submarine-force What You Should Know About the U.S. Naval Submarine Force], United Service Organizations (OSO) website</ref> ]] |