A nose-heavy torpedo naturally dives as it enters the water, and early fins did not fully correct the problem. Later tension wires helped the weapon belly-flop into the water, but this solution was still some way off during the First World War. In the raid calculation, about half the weapons strike the bottom and another quarter run too deep or otherwise miss useful targets. Only the remaining quarter are expected to run at a useful depth. Torpedoes are still preferred to bombs because the proposed attack aims to make battleships uneconomic to repair during the war. A ship could be salvaged from shallow water yet remain a wartime write-off.
Chapter · 23:32-31:31
Why early aerial torpedoes struggled in shallow harbors
Early torpedoes tended to dive, bottom out, or run beneath ships, while lax nets and cold, under-crewed ships could still make Wilhelmshaven vulnerable.