[washishu]

There is a config file that defines what short, medium and long range is.

Having absolutely no knowledge or understanding of code, it would not have occurred to me to look for that—and I wouldn't have known what I was looking at anyways. But I will take a look at that one.

the sonar operator seems to only report contacts within 20-22ish km.

That would explain why I have often heard something thumping away quite clearly and yet the op. says "No sound contacts". But it also works the opposite way too; the op. reports a contact and I can hear absolutely nothing.

Here are some range values that should help you make sound tactical decisions.

That's what I was after; I'll make a note of those. Although I never try to take on aircraft; I recall in one of the books—Iron Coffins probably as I've been re-reading it recently—that Dönitz tried to beat the aircraft attacks in Biscay by sending three or more boats out together and just wound up having three or more boats sunk. Coastal Command just sent out more aircraft and divided the boat's fire by attacking from all sides.

Thanks guys.