ASW is a numbers problem because the submarine begins as a concealed ambush predator. Small escorts resemble light infantry spread ahead of a formation to discover an enemy lying in wait. Those ships might detect the submarine directly or force it to reveal itself by attacking the outer screen. Larger or more capable escorts could then reinforce the contact and prosecute the target. The analogy explains why a navy needs many modest platforms alongside its more capable ships.
Notable Point · 2:03:50-2:04:57
An ASW screen needed numbers to expose an ambush
Numerous small escorts acted like a skirmish line, finding or triggering submarine attacks before they reached the main force.