When driving in deep sand, keep a few hessian bags behind your seat. If you become stuck, fill the bags with sand (overlap the tops to keep the sand sealed inside) and wedge them firmly in front of or behind the stuck tyre, depending on which way you want the vehicle to move. Sand gives way when pressure is applied, but when contained in a hessian bag, it cannot escape, so your vehicle will be able to free itself. Happy over-landing!
Quentin van den Bergh