U-boats searched a vast ocean using their best estimate of convoy routes, while escorts knew that any attacking submarine had to approach the convoy. An uneventful crossing already counted as success for the defense, and an attack could still end with U-boats lost. German boats primarily hunted merchant ships as part of an economic blockade, leaving the faster and more maneuverable escorts less attractive as targets. Britain could also replace those escorts more readily than Germany could replace submarines and experienced crews. In this interpretation, the 1938 Flower-class order gave Britain the cheap, numerous ships needed to answer a one-dimensional submarine campaign before the war began.
Notable Point · 12:02-15:59
Convoy geometry favors escorts
Convoy geometry made U-boats search for moving targets while escorts waited where an attacker eventually had to appear.