Japanese mines are described as capable weapons at the start of the Second World War. Japanese torpedoes also performed better early in the war than their German counterparts, especially in the air-launched role. The difference is attributed to heavier Japanese investment in torpedo development before the conflict. German aerial torpedoes became respectable by the war's end, which limits the comparison to early-war readiness.
Notable Point · 2:07:03-2:08:47
Japanese mine and aerial-torpedo investment
Japanese mines are described as capable, and Japan's better early-war torpedo performance is attributed to heavier prewar investment.