There has been no previous sea-floor surveying of vast areas of the Indian Ocean - and the small amount of sea-bed information previously available, came from satellite imagery.
The satellite imagery information about the sea bed was pretty indistinct in many areas, as you could well imagine with the sea depths in the search area.
The Fugro crews, marine scientists and the Australian authorities in general, have been regularly astonished at what the Fugro towfish have revealed about the sea bed in the search area.
The data has revealed many seabed features for the first time.
MH370 search resources - videos