It's worth noting that despite the introduction of the Hedgehog and later Squid ASW systems, Depth Charges remained the primary means of attacking submarines throughout the war and attained the greatest number of kills by the end.
The escorts held the line against the Wolf Packs for years. But what really led to the destruction of the Kriegsmarine was Aerial ASW. Performed by long range bombers and Escort Carrier hunter-killer groups. Eventually once the Allies had amassed enough Air Power in England they were able to effectively shut down Axis Ports in France and Italy as is. By 1944 most German Submarines were being sunk before they could even leave port.
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