In Enemy Hands (aka U-Boat)

At the height of Hitler's notorious U-boat war, the crew of the U.S.S. Swordfish is taken prisoner in a battle with a German submarine. However, meningitis strikes more than half of the German crew, and there aren't enough Germans to run the submarine. Avoiding both the contagion - and POW protocol - crew members and prisoners alike must work together to survive. But it isn't until a U.S. carrier locates the ship that the men aboard the U-boat are put to the ultimate test of will and survival.