USS Pennsylvania: The Largest Submarine in The U.S. Navy
You can't see her, she can dive to over 250 meters and stay down for 6 months. You can't hear her, she can run for over 20 years without refueling. She is the most lethal weapon. She is the USS Pennsylvania: The Largest Submarine in The U.S. Navy.
Watch this documentary to understand what an engineering marvel the USS Pennsylvania is.
