Anti-submarine warfare served the convoy's movement rather than an independent hunt for kills. A commander who delivered every merchant ship without sinking a U-boat succeeded; one who destroyed submarines after losing the convoy failed the actual mission. The same logic applies to submarines used as a mobile barrier against fleet movement: defeating their intended effect can be enough. This is a compact lesson in measuring naval success by the protected objective rather than enemy losses alone.
Chapter · 37:09-40:08
Convoy defense is measured by arrivals, not U-boats sunk
The decisive convoy metric was delivering merchant ships, even if no attacking submarine was destroyed.