Thats why you need a truck like mine for launching:
Its an 82, carbureted, no emissions junk...
Paid 600 bucks for it, 800 for tires, and waterproofed the ignition... stripped out all the carpet from inside, and drilled some drain holes...
I have had it in water, 3/4 the way up the doors, driven it in lakes, and huge mudholes, and still going fine...
If it breaks eventually, then i'll toss it and get another one heh.. but I have had it for 5 years now, and use it to launch wherever I want cause of the 4WD... and not put a dime in it other than oil changes.
The shallow ramps where I go, usually put me in the water at least to the middle of the rear tires...
If I launch on the causeway, then I have to go as deep as the doors sometimes... but hey, look at it! LOL who cares.
/edit - the only drawback is, it gets about 10mpg on a good day, usually around 8 LOL