The Taranto attack is used to illustrate how an existing plan could be updated to match the ships and aircraft available in wartime. The discussion argues that maintaining such plans was standard practice and extended to other foreign bases. Royal Navy sloop visits to Japanese ports are cited as occasions when harbor plans gained updated depth information. Small visiting vessels often occupied shallower berths, giving information about parts of a harbor that larger ships did not use. Those depths could help determine where torpedoes could operate. The link between the visits and prospective attacks is presented as an interpretation of the information collected.
Notable Point · 1:35:00-1:36:24
How peacetime port visits could inform torpedo-attack plans
Harbor depths gathered during sloop visits could give planners information about where aerial torpedoes would work.