Searchers for Titanic Tourist Sub Heard ‘Banging’ from Area

While the banging noise may have other origins, it sure sounds encouraging to the rescue effort underway.

However, I struggle to see how the submersible (or, more precisely, its passengers) can be rescued in time - not only does it need to be located, it also needs to be brought to the surface and then opened; there is no way to bring breathable air into the sub from the outside bar opening the entry hatch.

That's a lot of work which needs to be done in the next, what, 30-ish hours or so.