For deep sand, air down, 4low, everything off, and stay on the gas. 4high will work if you have the room to keep the speed up.

 

There was a part where i was going about 40mph it was pretty sweet

 

I usually use 4lo and don't touch the traction control (4lo turns it off). The trick is if it feels like your going to get stuck, like your only going about 5mph and it starts to feel like it's digging, power through. Not wide open throttle, but enough to keep you moving and accelerating. If you do get stuck, let off the throttle immediately. All you will do is dig deeper. Try reverse. Unlike in the mud where you turn the front tire back and forth to grab and pull you through, keep the tires straight. That goes for anytime on the beach. Most prime get stuck when they try to turn. If you're in a bad door just get through it before you try to turn around. Might have to rock a little, but not for too long. If that isn't working, get out the shovel.