The submarine's objective is merchant shipping, so escorts can meet the attacker by remaining beside its intended targets. Grouping merchant ships with armed protection makes a submarine approach a defended destination. In Custance's theory, Germany would eventually need a larger attacking force to overcome the escort, and Britain would answer with more defenders. Convoy could therefore drive concentration on both sides while bringing attacking submarines into contact with warships.
Notable Point · 1:02:57-1:03:50
Convoy as a way to force contact and concentrate defence
Convoy escorts wait beside the merchant ships submarines must approach, turning trade protection into an opportunity to engage the attacker.