> drive slow too through flooded section

This first requires knowing you're in a flooded section. That's the gap here, is it not? My point is that you can't use descent AS a "flooded zone" detection because then your speed, by the harsh mistress of psychics, is very limited everywhere you go, flooded or not, because stopping distance has to be kept very short since just a few feet of overshoot, when your flood detection triggers, is the difference between ruined engine or not.

Maybe that's their fix, if a flat mirrored surface is detected, slow way down, because perceiving depth of muddy water before getting in it is hard.