If there is at least one Western sub in the area there will be a Chinese one. Which can explain the handheld detector video and random shop course change to that area before ping received. It's a cover for the sub detecting it...
The UK does not have to cover up the sub they sent as it's about to retire and fitted with old tech. Hence the publicity about it being there being allowed/put out in the media. It literally is our least upgraded Nuclear sub we could have sent... I bet the Chinese sent thier best seeing the vested interest they have in finding this..
AIS image from last night. (24 hours or so ago)