No proper off roader can be complete without a portable air compressor. When the going gets tough, you're much better off if you adjust your tire pressure to suit the terrain the best. And once back on the pavement, it's equally important to bring them back to the factory recommended figures.
Under-inflated tires will flex more, crawling over sharp rocks instead of getting punctured by them. Having a wider patch will also increase traction where you most need it, hopefully saving you from sinking into deep sand or soft snow, if that's what you need to deal with.It makes driving off road more comfortable, and safer to the environment as well.
Our Aussie friends at Car Advice asked an expert about what pressures he would recommend, but as always, please remember that these numbers can vary depending on the weight of your vehicle and the tires themselves.