Eighty years after they were deployed for the first time to detect Nazi submarines during the Second World War, sonobuoys are aiding the hunt for missing Titanic explorers. The underwater sonar devices picked up banging noises in the area where the Titan submersible vanished, as searches continue for the vessel that dropped off the radar near the shipwreck on Sunday. Live updates on Titanic sub search Marine operations expert Mike Welham told Sky News that the sounds, which were heard at 30-minute intervals, suggest someone has "taken charge" of the sub and is "sending out the taps" in the hope...