Remember when I joined I was shown the way we dispatched U boats to the sea bottom with this anti-sub killer instead of depth charges. My first ship[Chichester] had Squid so I never really understood these Hedgehogs as I was Gunnery. Question for me is: 1. If they exploded on impact why didn't they do so after hitting the sea as they came down heavy and the fuse must have been sensitive? 2.after entering the sea surely they would drop down at a slower speed making it's contact with a sub not too hard[hence my question re.fuse sensitivity on entering the sea.] 3.Why did they not incorporate a depth trigger so they all went off at different depths if no contact made as that may have enveloped the sub in a deadly pattern,they did with depth charges . Now there is a good reason and answer for these questions that a TAS man can answer it's just I always wondered as they were successful it seems. Just an old man's curiosity if you can.