A guide to water crossings in your 4X4
Water crossings can make a weekend camping trip into a proper off-road adventure but they require careful planning to get right. Here’s everything you ever needed to know about water crossings in your 4X4.
This article originally appeared in Pat Callinan’s 4X4 Adventures Issue 42
River and creek crossings are a way of life as a four-wheel driver. They’re one of those rather incredible challenges that have become a rite of passage. Until you’ve waded down the Cox’s River out near Lithgow, driven the Crooked River Track in the Vic High Country, or bunted up the Old Telegraph Track in The Cape some may wonder whether you can even call yourself a real four-wheel driver. Your first crossing, if anything like mine, will be fraught with danger, stress, and an innate desire to cross every appendage you have in the hope of making it across unscathed or doing your best impersonation of a submarine.
A little bit of knowledge goes a long way, and if you get to read this before your first time, or even as a seasoned ‘Crosser of Rivers’, you may get some tips that can make your life just that much easier.
If it’s your first time crossing a particular creek or river, you’ll need to know how deep it is. If you’ve not crossed it in a while, it’s probably still a good idea to check the depth anyway. This requires walking the crossing in question, which will give you a good indication of how deep it is, and also what the base is like. Different depths and different base materials will then require different methods of how you drive it.
For example, a nice solid rocky bottom shouldn’t give you much trouble. You’ll want to take it easy, and slowly make your way across it. A sandy bottom should be driven the same way; however, care should be taken not to spin the wheels – spinning wheels especially muddies, will dig trenches and send you south.
The scary one, a muddy bottom, is where you will have the most problems. Momentum here is critical, and so long as you can gain some purchase on the bottom, either on hard-packed mud or anything substantial below the mud layer, you should make it across. If once you’ve walked a muddy bottomed creek and you sink past your knees into the mud, it might be wise to find another way around.
Interestingly enough, we had to cross Eyre Creek in the middle of the Simpson Desert while filming the TV show this year, and it was running hard. We found a crossing a few hundred meters off the QAA line, but it was muddy, and we sank through it when we went to walk it. The bypass track was a 70km round trip to the north, suffice to say we drove around, rather than getting stuck in a river in the middle of the Simpson Desert.
Another thing worth thinking about is how quickly the river is flowing. If it’s a raging torrent like you’ll see after a substantial amount of rain or a flood, forget it. Despite our four-wheel-drives usually weighing more than two tonnes, the water can and will wash you downstream quicker than you’d think. A good rule of thumb, is if you can’t stand up in the flowing water with your legs together, and it keeps trying to push you over, it’s probably flowing too fast.
KNOWING HOW TO DRIVE IT
Momentum. This is the key to many four-wheel-driving adventures, especially so those involving water crossings. You want to keep your momentum up and drive at a speed that will give you a nice bow wave in front of your bull bar – think somewhere in the vicinity of 5-8km/h – a brisk walking pace. This bow wave creates a depression in the water behind your bullbar, and keeps your engine and gearbox out of the water; so long as you keep the momentum up.
Don’t charge headlong at a water crossing at 40-plus km/h with the hopes of getting an epic photo of water spray 30-feet over your roof. Sure, it’ll look good to show your mates, but the damage it’ll cause is just not worth it; especially miles from home. Hitting a crossing too quick will often damage bar work, radiator, thermo or mechanical fans, and there’s a good chance you’ll tear your number plate off. That’s not to mention the unpredictable response you’ll get out of your four-wheel drive, like spearing off the crossing into the bush, or cleaning up whoever is taking the photo.
Take it easy, be mindful not to bounce on the accelerator pedal, and you should be alright.
KNOW AND PREPARE YOUR VEHICLE
Just driving headlong into the water without knowing your vehicle is one of the biggest mistakes you can make. Having a snorkel will certainly help, but if not, knowing what your maximum wading depth is for your vehicle will get you started in the right direction. Airing down will reduce your height a touch as the tyres deflate, but will allow for better traction when crossing.
Understanding the difference between a snorkel and raised air intake is another critical point. A raised air intake is often not hard sealed and can take air (and water) in below the snorkel head. The old factory option Nissan ‘snorkels’ were actually a raised air intake; the Nissan badge on the side of the snorkel at bonnet height was riveted on and was not sealed. Suffice to say we caught up with a bloke many moons ago up in Cape York who drowned his Patrol and hydro-locked the engine due to water coming in through the Nissan badge.
As we were talking about the bow wave earlier, a water-blind for the front of your four-wheel drive is a good bit of kit to have if you’re planning on doing a lot of crossings. It helps create and maintain the bow wave and stops water coming through your radiator. Why this is so critical, is that if you get a lot of water behind the radiator at the same level as the fan, your fan blades will pull forward, often into the back of your radiator. A busted radiator halfway up the OTT is not ideal.
A note on breathers. To complete a crossing, you don’t need extended breathers for your diffs or gearbox. It will cross just fine. It’s the 400km home from your trip where your oil has turned to a chocolate milkshake and is no longer lubricating the moving parts you’ve got to worry about. A cost of a set of breathers is usually under $100 and can be installed yourself without too much hassle in an afternoon. Cheap insurance for your driveline, especially if you’re a long way from home. There’s really no reason not to get extended breathers for your driveline, especially due to the benefits they provide.
Make sure you’ve got your recovery gear handy. This is non-negotiable and will quite possibly save your four-wheel drive if you do get tractionally challenged. Trying to open doors and drawers to get your gear out when you’re stuck adds to the stress and the amount of water you’ll get in your vehicle.
Having it handy is a great start, having it already out, attached, and ready to go is just that much better. More often than not, if I’m driving a harder crossing, I’ll already have the snatch strap attached to the hitch receiver at the back of my four-wheel drive, and spooled up on the roof cage. Should I get stuck, all I need to do is reach up, grab the strap, and throw it back so my mate behind me can connect up and pull me back. Same too for a winch at the front; have it unspooled with the controller connected ready to go, with the hook on your bullbar, and the rope spooled out on the bonnet; this doesn’t work so well when you’re running steel cable.
Remember that water-logged straps and winch ropes are heavier, and therefore have greater kinetic energy if something were to let go, so make sure you throw a dampener over them.