The arrival of advanced escorts in World War I would give Germany a reason to change its submarine tactics. One proposed response is a larger submarine whose guns could engage beyond the escorts' range. That proposal is challenged on stability and fire-control grounds: a submarine is a poor gun platform, and a destroyer's guns and rangefinders sit higher above the water even when its freeboard is low. Nominal gun range therefore does not establish an effective advantage in a surface duel. The original contributor clarifies that German adaptation is the main point, rather than a firm claim that cruiser submarines would solve the problem.
Notable Point · 55:50-57:50
Why larger submarine guns would struggle against destroyer escorts
A larger submarine's nominal gun range would not remove the disadvantages of an unstable platform and low-mounted rangefinders when fighting destroyers on the surface.