I actually had this concern in an earlier comment… it’s very likely that militaries may already have the capabilities needed but can’t (and probably shouldn’t) disclose them.<p>It’s the tradeoff between 5 civilians and potentially hundreds or thousands of sailors in wartime.<p>[1]: <a href="https://news.ycombinator.com/item?id=36416052">https://news.ycombinator.com/item?id=36416052</a>
This has happened before - US Navy was able to pinpoint the exact location of soviet K-129 shipwreck using recordings from spy hydrophone array after they observed search and rescue efforts from soviet navy. It was laying hundreds of kilometers away. [1]<p>[1]: <a href="https://en.wikipedia.org/wiki/Soviet_submarine_K-129_(1960)" rel="nofollow noreferrer">https://en.wikipedia.org/wiki/Soviet_submarine_K-129_(1960)</a>