The cargo ship was the main vessel of the United States Navy during WWI.
It carried troops and equipment to war zones, and served as the backbone of the U.S. naval fleet during the war.
In the 20th century, the U-2 spy plane was based at NAS Pensacola, Florida.
The U.K. launched its own U-boat and a submarine from its Royal Navy base, HMS Queen Elizabeth.
The Russian submarine was named after a famous Soviet submarine.
A U-8 biplane was built by Lockheed and operated in the 1970s and 1980s, but the plane was retired in the early 2000s.
Today, the Boeing 747 is the most commonly used aircraft for the U.-2.