1-I wade because I can.
2-I know what's under the water.
3-everything under the truck is sealed and waterproofed all ready. It is an offroad truck sold the world over for just that...offroad.
4-raised air intakes are NOT meant to keep out water, only to get to the air higher up away from the dust.
5-if you check for water ingress after you wade and find none, no need to do anything.
6-I drove in water up to the door handles all the time in my Land Rover, never once had a problem. I've even had the water break at the base of the windshield. That was scary. But that air intake was in a different location.
7-petrol engines are not waterproof, that's why raised air intakes are not meant for water on petrol engines.
8-it's fresh water, it is how I rinse the underside of the truck in the spring to get all of the road salt off.
9-it's an offroad truck. It's not a Ford Explorer.
10-everything under the truck is meant to get wet and be submerged with no ill effect. Otherwise every time it rained you wouldn't be able to drive.