The Type 97 81 mm infantry mortar also served in anti-submarine work. The word mortar can refer to more advanced depth-charge launchers in some descriptions. These projector systems differ from simpler throwers. The variation reflects both the method of launching the weapon and fluid contemporary terminology. A reference to a mortar therefore needs context before it can establish exactly which system was fitted.
Notable Point · 28:32-29:11
Mortars, projectors and fluid weapon terminology
Japanese anti-submarine terminology can refer both to an infantry-derived mortar and to more advanced depth-charge projection systems.