The Largest Submarine in The U.S. Navy (Video)

From YouTube: USS Pennsylvania is a United States Navy Ohio-class ballistic missile submarine which has been in commission since 1989. The Ohio class is a class of nuclear powered submarines used by the United States Navy. The Navy has 18 Ohio-class ballistic missile submarines and guided missile submarines.

Update: 27 Incredible Photos Of Life On A US Navy Submarine -- We Are The Mighty