I'm surprised that no one has responded to your post. I don't feel qualified to answer your question, but I've pushed out more than one drowned vehicle while hunting in the Florida Everglades. I do not believe you are going to be able to set up a Jeep or any other vehicle to swim long distances in deep water. However, there are some things that you can do to avoid getting stuck if you misjudge the depth of a stretch of water.

!. Lift kits - yes, the ones the rednecks use on their Ford F150s. I believe that this is the only legitimate use of these things. You can really destroy the handling and increase the roll-over potential of the vehicle this way, but it will get through deeper water.

2. Snorkel the intake - most vehicles die in deep water when they suck water in the intake and become hydrolocked. If you run a hose to the intake and make it higher (just look at some of the big rigs), you decrease the chances of getting water in the intake.

3. Snorkel the exhaust - the other engine killer is back pressure. When water covers the exhaust pipe, back pressure from the water can prevent the engine from running.

If you get in deep enough and long enough, you are eventually going to short the ignition system regardless. The measures I've listed here might get you through some deep puddles, but not much more than that. The scenes from the movie Dante's Peak where Brosnan's character fully-submerges a Suburban in a river and drives it out the other side is nothing but fantasy.

Now, the GIs in WWII, would wrap their Willy's Jeeps in canvas so that the would float and row them across a stream, then crank em up and keep going. There might be an idea there.

Stay dry.

Craig.