Torpedo defence includes evasive maneuvers, passive defense like

torpedo belt The torpedo belt was part of the armouring scheme in some warships between the 1920s and 1940s. It consisted of a series of lightly armoured compartments, extending laterally along a narrow belt that intersected the ship's waterline. In theory thi ...

torpedo net Torpedo nets were a passive ship defensive device against torpedoes. They were in common use from the 1890s until the Second World War. They were superseded by the anti-torpedo bulge and torpedo belts. Origins With the introduction of the White ...

torpedo bulge The anti-torpedo bulge (also known as an anti-torpedo blister) is a form of defence against naval torpedoes occasionally employed in warship construction in the period between the First and Second World Wars. It involved fitting (or retrofitting ...

s and active defenses, like anti-torpedo torpedoes similar in idea to

missile defense Missile defense is a system, weapon, or technology involved in the detection, tracking, interception, and also the destruction of attacking missiles. Conceived as a defense against nuclear-armed intercontinental ballistic missiles (ICBMs), ...

systems. Surface Ship Torpedo Defense and Countermeasure Anti-Torpedo systems are highly experimental and the US Navy ended trials on them in 2018.

References

Torpedoes Naval warfare tactics {{Mil-stub