The U-boat packs were kept underwater and harried continually.
Here is the SMS Vulkan, sub tender for the North Sea U-boat fleet.
One night his ship, the Stork; pursued and rammed a U-boat in the darkness.
In anti-U-boat warfare the air weapon was now an equal partner with the surface ship.
When ship's crew is rescued by deep diving lifeboat, the key problem is how to find the position of life-saving platform accurately in order to joint with U-boat.
The Casablance Conference had proclaimed the defeat of the U-boats as our first objec tive.
