 Mare Island was selected by the Navy for construction of the only US West Coast-built dreadnought battleship, , launched in 1919.In 1904, the pre-dreadnought battleship had been launched at Seattle, Washington.Noting the power of underwater warfare shown by German U-boats in World War I, the Navy doubled their Pacific-based submarine construction program at Puget Sound Naval Shipyard by founding a submarine program at MINSY in the early 1920s.