The engine was full of water...  you could hear it.
They (as ever) knobbled the 'professional' on the event... in this case they make a 30m long, 3' deep water run to get through.  For their machine (2' ground clearance) it wasn't a problem.   Drew went in a bit quick, made a big splash and sucked water in.   
He was over 1 minute ahead at that point.