Torpedoes promised to make a ship sink quickly by opening it below the waterline. The simplified damage distinction is between fire the crew cannot extinguish and flooding through a hole the crew cannot close. Letting air into a ship does not produce the same result. A torpedo's ability to create uncontrollable flooding therefore suited the demand for a rapid killing blow.
Notable Point · 1:06:10-1:06:59
Why torpedoes promised a rapid fleet decision
A torpedo could produce a rapid decision by causing flooding that the target's crew could not contain.