Hedgehog Hedgehog was a multiple spigot mortar, which fired contact-fused bombs ahead of the firing ship while the target was still within the ASDIC beam. These started to be installed on anti-submarine ships from late 1942. The warship could approach slowly (as it did not have to clear the area of exploding depth charges to avoid damage) and so its position was less obvious to the submarine commander as it was making less noise. Because hedgehog only exploded if it hit the submarine, if the target was missed, there was no disturbed water to make tracking difficult—and contact had not been lost in the first place.
Hedgehog Hedgehog was a multiple spigot mortar which fired contact-fused bombs ahead of the firing ship while the target was still within the ASDIC beam. These started to be installed on anti-submarine ships from late 1942. The warship could approach slowly (as it did not have to clear the area of exploding depth charges to avoid damage) and so its position was less obvious to the submarine commander as it was making less noise. Because hedgehog only exploded if it hit the submarine if the target was missed, there was no disturbed water to make tracking difficult—and contact had not been lost in the first place