Not sure about your area but over here it is really bad juju to be driving up the creeks and rivers just for the fun. Some water crossings can't be avoided and that's just part of the game. But as a fisherman I'm really not a big fan of driving in creeks and rivers. Slip off a rock wrong and split the oil pan, damage a radiator hose, peel the rear diff cover back over a rock..all bad situations made worse when that stuff leaks into the water. Plus unless it's part of a 4wd trail it or sanctioned park/private property it makes all of us Jeepers and Offroaders look bad when and innocent little drive turns into a small eco disaster and that's what gets area and trails shut down. The headline over here would read "renegade Jeepers destroy local trout stream with illeagal antics" Even if no oil was spilled the tire tracks alone would be enough to get the area closed to vehicles...Ok rant off..
From the offroader veiwpoint I'd be more worred about my diff, trans and transfer case breathers. With water that deep just give up and expect your carpets and seats getting soaked! Clean that up later. But yeah, extend those breathers!
Go Play Outside.