Interesting interpretation :hmm: The sound certainly seems closer to any underwater generated impulse so far
, yet the second part is what makes me doubt. First, because the rattle should only be heard when the beam is actually trained to your sub, and the waves actually reach the hull (Wether they are strong enough to generate a visible response to the ASDIC operator, that's a different matter). Second, because I somehow expect a larger time difference between emision and rattle, though of course that will vary largely depending on the distance of the emmiter. Of course, this last comment is a rather subjetive indication because since the audible and non audible waves travel at the same speed through water, you will actually hear them together. In that regard, the sound is correct.
But as I said first, it is really the best underwater ASDIC I've heard so far. Installed for staying