Sand Driving 101
There are three golden rules to avoid getting bogged in sand, but, sooner or later, getting stuck is inevitable.
There is a black art to driving on sand. To the uninitiated, undulating dunes are like vertical quicksand and soft patches on beaches - like at Robe and Yeagurup - can be frustratingly difficult.
When heading out for some sand driving, there are three vital things to remember. Firstly, everyone gets stuck in the sand at some point. It's going to happen, so just accept it so you can get onto figuring out what to do next. The second and third points concern the concepts of flotation and momentum - understanding these will help you avoid getting bogged in the first place. Once you master these, you shouldn't ever get stuck in the sand again, even if you are towing. And when you do, you'll understand how to get out.
EVERYBODY GETS STUCK
A problem faced by many tackling sand driving, be it on a beach or in a desert, is not a mechanical one, and you won't find it mentioned within any physics textbook. It's essentially an ego problem, and it's called cognitive dissonance - when the world demonstrates that the little white lies your ego tells itself are wrong. So when people realize they are about to get stuck in sand despite doing what they think are all the right things, they get mad. They step on the accelerator, which just digs the wheels in until the car is resting on its hubs and bash plates.
Ironically, when you accept you're going to get stuck no matter what, you don't get stuck as much. And when you do, you know to stop immediately, and stay off the brakes and the gas. Braking on sand can build up little piles of sand in front of the tyres that make it hard to get started again. Stepping on the gas only works when you're already on top of the sand, and it is done sparingly - which brings us to flotation.
The trick when you're driving in sand is to stay on top of the stuff; you want to float across it. And the more sand you can displace, the more you will float. One of the easiest ways to displace more sand is to reduce your tyre pressures. This forces the sidewalls of the tyre to bulge out while lengthening the tyre's footprint. There are a million theories on how low to go (and a lot of misinformation about running tyres off rims when the pressure is too low).
I usually go down to anywhere between 15-22psi, depending on how heavily the wagon is loaded and whether I'm towing. You can take the tyres right down to 8-9psi if things get hairy. There is always the risk of running them off the rims, sure. But when the tide is coming in, a risky choice is better than no choice at all.
Let your tyres down properly and you'll be amazed how much easier your vehicle handles in the sand. It will confidently climb dunes and glide effortlessly over the softer sections on beaches. You'll still slow down, but the tyres won't dig in so much.
A happy consequence is that this also makes your ride much softer, which comes in handy when you're working on the momentum side of the equation.
Lower pressures are also handy because a lot of driving on the sand is about maintaining momentum. As long as you're moving forward, you'll have better flotation. Think of your car as a skimming stone. While it is sitting flat and wide and moving along, it stays on top of the water. As soon as it either slows down or its footprint decreases, it sinks like a stone. Your vehicle is exactly the same on sand, so keep the pedal in once you get moving. It's going to be a rough ride sometimes, especially if you're going up scalloped tracks on sand dunes. You don't have to hoon it, and try not to accelerate too quickly - just make it smooth and steady.
As we now know, you're going to get stuck no matter how good you are. I can go years without getting stuck in sand, but I know it's going to get me sooner or later. There are a few simple tricks you can use without getting out of the car - although with most of these methods a long-handled shovel comes in handy, to dig out any piles of sand that have built up around your tyres. Don't dig too close to the tyres, though, as you can end up with your fourbie's belly on the ground. Then you'll need more than just good driving!
This is where you put the car in first gear, get the wheel to roll forward, stop before it slips and let it roll back. Sometimes you can time your gear changes to coincide with this gentle rocking. You're flattening out the sand under your tyres and packing it down. Once you've done this a few times, quite often you can just drive away.
Handbrake Traction Control
By pulling gently on your handbrake while accelerating slowly, you can force the wheels to turn slowly instead of spinning. This can work to get you out of a shallow sand bog, and also works great in mud.
It isn't easy when you're towing, but if you can back off from the point where you got stuck, you can have another fresh go from better packed sand, or a flatter spot.
This should be at the top of your inventory list, since you'd be silly to be doing hard sand driving without a buddy. And a buddy with a snatch strap is all you need for about 99% of sand boggings. Just bear in mind that snatching can be dangerous, and all spectators should stand well clear.
I've been winched off beaches where the sand was too soft and steep for snatching - the other car just got stuck too. So a winch comes in handy to work from further away. You can also use a sand anchor or bury a spare tyre if you're alone.
Maxtrax recovery aids are expensive, but they work a treat, giving you just enough momentum to stay on top of the sand once you drive out of the hole you've just dug with your tyres. A cheaper option is your vehicle's floor mats.
Sometimes sprinkling a bit of water on the sand around your tyres is enough to pack it down and help the rubber get some traction.