Porpoise class

As Porpoise class (. English porpoises ) are referred to three decommissioned boat classes U:

• the British Royal Navy used six Porpoise-class (1933) (also Grampus-class ) underground mines between 1933 and 1946
• the US Navy used ten Porpoise-class submarines between 1935 and 1956 (1935)
• the British Royal Navy used eight Porpoise-class boats between 1956 and the mid-1980s (1956)

This is a disambiguation page for differentiating between several terms identified with the same word.