Regarding trucks and water crossings just remember, trucks are not boats. They are not built water tight and if you go in deep water it will begin to seep into places it doesn't belong. You may cross deep water and and believe you had no issue, but that is not always true. You just didn't notice a problem right away. I have seen problems caused by water infiltration. It can get into an electrical connector and cause corrosion over time that can give you an intermittent issue months later. It can get under the insulation and carpet on the floor and cause mildew over time. It can get in a differential and cause bearing or gear corrosion over time. Etcetera. You can cross whatever depth you are comfortable with, but just be aware of all the risks.