 Filming primarily took place between 9 July and 11 August 2007 ; the first scene filmed depicted the group being accosted by the Host while crossing over the engines . On 12 July , Tennant 's mother , Helen McDonald , began to succumb to her cancer . Filming was rescheduled to allow Tennant to be present when she died and was buried ; she died on 15 July and was buried on 21 July . During Tennant 's absence , scenes in the Titanic 's reception area were filmed at the Exchange in Swansea and the Coal Exchange in Cardiff Bay . Tennant filmed his scenes in the area on 16 and 17 July . The last use of the Coal Exchange was on the 18th ; scenes depicting the ship 's collision with meteors were filmed on that day . 
