Having never attempted a crossing first hand, "generally"... IMO, would seem to be the correct word to use in describing water infiltration. There are a few factors to take into consideration....length of the crossing, strength of current, etc. Again, please re-read my initial statement and take everything I just said with a grain of salt! Lol, I'm a Floridian and we have almost zero "crossings" other then a swamp or two. Have fun!!

 

I've done quite a few water crossings and have had water several inches up the door. I have never had water creep into the cab. I would suggest (not sure if this was covered yet) that you relocate the front/rear diff breathers and transfer case breather if you plan on or may encounter deeper than normal puddles

 

I have the plastic diamond plate sill guards, so a little water can get in. I'd say maybe a couple teaspoons at each door for a longer, deeper crossing. Really not a problem as long as I don't get stuck out there. If you don't have sill guards, that is a tight seal--you shouldn't have any leakage.