The submarines were either called "submarines" or "U-boats." The German submarine was called the "U-boat"
Perhaps you're thinking of the liner Lusitania which was sunk by German submarines during World War One.
There are no drivable submarines in Just Cause 2, but one is featured during the events of the game.
There are different answers to that but the most common one is that the USN had 288 submarines in WW2
Germany must surrender its submarines and weapons
The "wolf pack" was a strategic grouping of German submarines (U-boats) during World War II, whereby more than one German sub might attack the same Allied convoy crossing the Atlantic.
Oilers then merchantmen.
One of our Submarines was created in 1982.
Only one US submarine sank in World War One.
The Imperial Japanese Navy started World War II with one of the largest submarine forces in the world. Despite the sinking during the war of several major U.S. warships by Japanese submarines, the Japanese were never able to effectively employ their submarines to any great extent. Japanese submarines tended to operate alone and were directed toward tactical gains. The United States, in contrast, employed wolf packs, embraced new technology, and engaged in a campaign of strategic submarine warfare. On Dec. 7, 1941, during the attack on Pearl Harbor, there where 3 Japanese submarines stationed in a picket line 100 miles forward of the carriers. They were the I-23, I-21, and I-19. There are even rumors of Japanese subs patrolling the East Coast during the war.
One successful tactic Germany used in World War One was submarine warfare. It lacked the navy Great Britain had. Building submarines was the fastest and least expensive way to have a military presence in the seas and oceans.
Sonar was used to detect and hunt submarines in WW2
ONE