Titan sub: David Mearns speaks of missing friends on board

David Mearns, a search expert who is nicknamed the "shipwreck hunter", knows two of the five people on board the missing Titan submersible.

He says the two men are experienced explorers who he imagines got on "fantastically well" upon meeting.

Mr Mearns helped in the search for footballer Emiliano Sala, when his plane went missing over the English Channel in January 2019.