The first US Navy destroyer to be lost in combat was the USS Jacob Jones, sunk by the German submarine SM U-53 6 December, 1917. The ship's brief history, and its loss- the only US destroyer lost during the great war- represented the risks faced by, and heroism of, the men of the US Navy in that war.
The first class of nuclear submarines were a learning experience for the Soviet Navy. The November class boats experienced numerous difficulties and accidents, culminating in what has been described as a potential “Underwater Chernobyl."