Current focus area
For the not so technically minded, zoom into one (or any) of the sub-sea features in the search area using Google Earth and look for the stitch patterning and snail-trail tracks.
These represent and give some idea of the extent of higher resolution survey conducted in these areas of the ocean between year dot and now.
The snail trails terminating in Fremantle are probably the work of the old HMAS Diamantina in the '70's / '80's'
That leaves a hell of a lot of ocean floor as soft-focus guess work.
Now try and work out how long the new target areas might take to cover!