What strategy did convoys use to help the allies combat German submarines warfare?

Answer 1

They had difficulty in combating merchant convoys to and from their overseas allied nations, as German submarines were a huge threat. Their main tactic was the use of depth-charges, which even if they did not hit the submarine directly, created an overpressure effect which could rupture a sub's hull. They also relied heavily upon heavily-armed naval escorts which had the capacity to fire ship-borne torpedoes, as well as upon their own submarines to track and hunt down German and Japanese ones.