Preparing your rig for water crossings needn’t be expensive. A little patience and a few skills will take you surprisingly far.
Check for holes in the floor pan and firewall and then seal them up; a nut and bolt, flat washer and sealant will usually do the trick.
Factory fitted air filter housings are rarely submersible, but you can seal them up before you go. Just remove the housing and place it underwater to spot the leaks. Don’t forget to check the intake tubing for leaks as well.
A breather extension kit will let you move the diff, gearbox and transfer breather hoses to a higher location, to prevent them from being completely submerged during a crossing.
To save your camper’s bearing hub against water damage on those famous Cape crossings why not fit marine-grade seals often used in boat trailers? They’re readily available and easy to fit.
Here’s a real simple second line of defence against water ingress that’s easy to fit and costs next to nix. You’ll need to check the micron rating (filtration level) matches the specifications in your fourbie’s fuel system requirements first though to avoid impacting your vehicle’s performance.