There is now a race against time to find the deep-sea vessel that went missing on Sunday while on a trip down to the Titanic wreckage off the coast of Canada. The submersible, named Titan, lost communication with tour operators about 435 miles south of St John’s, Newfoundland, and the US Coastguard predicted the vessel would run out of breathable air around 10am GMT on Thursday. Here’s what we know so far.