There's a radar in the ship that scans the bed of the water and gives a simplified view of the riverbed. You can see it with the rainbow color display at 2:11 to 2:15. I don't know what the colors signify though, unfortunately! Depth of the riverbed, I presume.
Jeez, was that it? No finds or revelations - just 6.23 minutes showing what a boring task it is. Hope the operator is being paid per view, otherwise why else participate?
