An oceanographer, who co-led an expedition to create the first map of the Titanic on the ocean floor, believes authorities should narrow their search for the missing Titan to a five to ten kilometre circle of the shipwreck.
David Gallo's best friend is Titan passenger Paul-Henri Nargeolet, a 77 year old retired French Navy commander who has visited the Titanic wreck more than 35 times.
He says if Mr Nargeolet is still alive, it's likely he's the one searchers have heard banging. Oxygen is due to run out onboard the Titan just after 11PM New Zealand time.
Earlier this afternoon, Mr Gallo told Lisa Owen about the journey to the Titanic.
