Historically and in-game, U-boats were most dangerous when used as "submersible torpedo boats." Attacking on the surface at night gives you a speed advantage over most merchant ships and makes you very hard to spot.
These specialized torpedoes (available later in the war) can be programmed to travel in a zigzag or ladder pattern. This is incredibly effective when firing into the middle of a dense convoy where a straight-running shot might miss. Stiller Jäger 3
While tempting to use against defenseless merchants to save torpedoes, the deck gun is useless in rough seas and leaves you vulnerable. Only use it when you are certain no escorts are nearby. Historically and in-game, U-boats were most dangerous when
When being hunted by destroyers, toggle "Silent Running" immediately. This stops all non-essential repairs and reloading, which are noisy and give away your position to enemy sonar. While tempting to use against defenseless merchants to
"Stiller Jäger 3" (Silent Hunter 3) is a legendary submarine simulation game focused on U-boat warfare during World War II. To master it, you need to move beyond simple "point and shoot" mechanics and embrace the technical realities of manual targeting and crew management.
Sound is your best friend when submerged. You can track convoys far beyond visual range by manually listening for propeller noises. A skilled player can identify ship types and even calculate their speed just by counting the "RPM" of the screw sounds.