Auto-sub used for scanning ocean floors
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Malaysia Airlines flight MH370: Giant sub drafted in to find plane

28 April 2014 Last updated at 23:11 BST

As the search for Malaysia Airlines flight MH370 draws a blank, the BBC's Richard Westcott reports on the kind of technology that is being drafted in to help step up the investigation.

It includes an auto-sub to map the ocean floor, which can dive 1.5km deeper than any submarine used before.