A conventional torpedo's diving run could bury it in a shallow harbour bottom before it reached a target. Wooden fins and a tension wire helped hold the nose up and produce a flatter, belly-flop entry. The weapon could settle into its run at a useful depth rather than ploughing into the mud. This accumulated technical knowledge was a major reason the raid was feasible in 1940.
Notable Point · 1:33:26-1:36:12
Making an aerial torpedo work in a shallow harbour
Wooden fins and a tension wire helped British aerial torpedoes enter the water shallowly enough for Taranto.