I've done river crossings in the Jeep where it starts to get light and almost float, scary stuff. I can't imagine doing that in something as heavy as my truck. Old jeeps at least were made for that. The drain holes were already in the floorboards.
Water sucks. Be prepared to check oil in the diffs, tranny, trasfer case, wheel bearings etc. Ask me how I know.
Ah yes, the University of Hard Knocks. I know it well.
Mike