Everything you need to know about water crossings

ByIsaac BoberDecember 23, 2019
Everything you need to know about water crossings

Water crossings can take a simple drive in the bush and make it feel like a proper adventure. Here’s everything you need to know about water crossings.

It was 2010, and I’d just turned off the A699 somewhere near Roxburgh Castle. My destination was Floors Castle and a meet and greet with the Duke of Roxburgh. What, ho. With the Tweed River ahead of me, and a Land Rover Experience instructor waving madly at me, I did as I was bid, and dipped the snout of the Land Rover Discovery 4 into the river.

Keeping the Disco’s nose pointed at the instructor standing downstream on the opposite bank, I made it across the bonnet-high river just in time for tea and scones. And this was not at all the way you should cross a river.

See, I had no idea how deep the water was, sure, there was a bloke standing in it with the water lapping at his chest, but I couldn’t see the exit when I entered the water. The river was fast-flowing and not long before hitting the water I’d been frapping along for several hours getting all the mechanical bits and pieces nice and hot. There was no time to let things cool down and there was no recovery gear in the vehicle.

This was the launch of the Land Rover Discovery 4 and while there was an Arctic Trucks-spec Defender 110 on stand-by and a dozen or more Land Rover Experience instructors pointing and directing vehicles, there’s a lot more to driving through water than just rolling up to the water’s edge and diving in.

Know your vehicle

Water crossings can be a whole heap of fun and add a real sense of adventure to any off-road drive, but it’s important you’ve got a good handle on your vehicle. For instance, make sure you know the maximum wading depth, and if you’ve got a snorkel fitted make sure it’s properly sealed against water ingress. Some of them are there just to get clean, non-dusty air rather than being sealed against water.

The airbox is another area where we’ve heard some dodgy over-the-fence advice, like one bloke who suggested blocking the drainage holes in the airbox with silicon to prevent water from getting into it. Hmm, what about when it rains, or you wash your 4X4 and water splashes down the snorkel…if the drainage holes are blocked up then the water will just puddle. The airbox should already be fitted with one-way plugs that allow water to drain but not be pushed up inside from beneath. If the plugs in your vehicle’s airbox are missing, then make sure you fit a new set.

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This is the sort of stuff you should be doing before a trip rather than when you’re pulled up at the edge of a river. Most 4X4s have differential breathers fitted but these often don’t sit high enough to stay clear of water (often they terminate just above the height of the wheels somewhere on the firewall). Ideally you want them terminating as high as possible in the engine bay to minimise the chance of them sucking water into your diffs while crossing a river. If water does get into the diffs, well, you can kiss goodbye to the diffs (click here to read about how easy it is to fit a set of aftermarket diff breathers). You should also look at fitting extension breathers on your transfer case and transmission, for the same reasons.

Another area to be aware of is your vehicle’s electrics – and this is another check you should perform on your driveway, as is a good once-over of your vehicle’s door seals. Most modern 4X4s are fitted with waterproof plugs and the critical components placed higher in the engine bay to keep them away from water. Some, like the new Defender’s electricals, have been designed from scratch to be immersed in water for hours and still work. That said, some sort of water dispersant-esque spray, like WD-40, sprayed onto the under-bonnet-vitals is still a good bush stich-in-nine practice before you dip your vehicle into the drink.

While you’re spraying some of the bits under the bonnet, it’s a good idea to check your tyres and make sure there are no cuts or chunks missing. There’d be nothing worse than a flat tyre half way through a crossing.

And the good thing about all this wandering around before you dive into the water is that you’re giving your 4X4 a chance to cool down, because hot things don’t mix well with cold things.

Once you’ve got back home, it’s a good idea to give your vehicle a good once over. Make sure there’s no water still sitting in things like fuse boxes. Take a look at the radiator and cooling fan for signs of damage, and check the engine oil and transmission fluid dipsticks for discolouration that could suggest water has made its way in. If you’ve been through a handful of water crossings on your adventure then it’s a good idea to check the diff oil, but if you’re not mechanically minded then get your mechanic to check this out.

Anything else about my vehicle?

Water blinds can be a useful piece of kit if there are a lot of water crossings in the area you like to go driving. Too many cheapskates go for some poly-tarp and stretch it across the front of their vehicle with bungy straps, only for it to fall off mid-crossing. Honestly, you’re better off here just spending some extra cash and buying a proper water blind which will be shaped to suit the vehicle’s snout (even if it’s got a bull bar) with sturdy straps. Just remember to remove it once you’re safely out the other side of the water; as prolonged covering will starve your vehicle of its cooling ability.

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Make sure you’ve got your recovery gear handy; make sure your winch (if you’ve got a winch) is ready to go; meaning it’ll likely be uncoiled and secured on the bonnet, or that your snatch strap has shackles connected and is attached and coiled in the car or on the bonnet. Basically, you don’t want to be fiddling around if you do become stuck as time is of the essence when you’re stuck in a river.

The crossing itself

The most important thing(s) you need to ask yourself is/are whether you actually need to drive through the water (sure it’s fun but it might be safer to overland your way around), do you know where the exit is if it’s not directly opposite the entry, is your vehicle set-up properly (recovery gear ready), and will I be doing unnecessary damage to the environment?

If you decide that you do need to cross at this point, then, unless you’re familiar with the crossing or have just watched another vehicle drive it you’ll need to get out and get your feet wet. Water crossings can be deceptive with the water acting as a magnifying glass and making it seem that the water isn’t as deep as it actually is. More than that, the exit may be out of sight – as it is with one of our favourite local crossings. That said, if you’re in the northern parts of Australia, where crocs live, then walking the crossing is not an option.

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So, what happens if you can’t walk the crossing? Well, local knowledge helps here. If you know you’ll be visiting an area you’ve not driven before and that there will be water crossings, then maybe check on forums to see if anyone else has been that way. Or if you’ve arrived at the crossing and there are other four-wheelers around, then ask them what the crossing is like.

But, as a general rule of thumb, faster flowing water will have a more solid base while slower water will be softer. And, if you do hop into the water and are struggling to stand up, then don’t attempt to drive across it. Find another way around. Similarly, if the river is in flood, or indeed if you’re driving anywhere where it’s flooding, don’t be a fool and try and drive through swollen rivers. It’s a recipe for disaster that could result in your vehicle being washed away and you drowned.

Enjoying the drink

Once you’re all set, make sure you’ve selected 4WD Low-Range and, if you’re driving an automatic you can either select D for Drive or manually select second-gear, if possible. Similarly, in a manual-equipped vehicle, choose second-gear.

Once in the water you’ll be shooting for a fast-walking pace of around 7km/h – although if the base is muddy and soft then you’ll need a little more momentum.

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The idea when driving through water is to create a bow wave in front of your vehicle rather than splashing and sloshing the water across your bonnet. Sure, you’ve all seen YouTube videos of people driving through crossings like loons, but what you probably haven’t seen is the engine cooling fan slamming itself into the radiator which can happen if you hit the water too hard and bend the fan blades. A water blind, obviously, helps reduce the risk of this happening, as does entering and driving at a steady pace across the water.

Get your speed right and the bow wave being created by your vehicle will create a depression behind the wave, reducing the height of the water where your engine is sitting. That said, drive too slowly and this depression behind the wave will fill again. You don’t want to be adjusting the throttle once in the water, or changing gear either, just get your speed right, hold the throttle steady and focus on your path through the water.

A quick note. Generally speaking, when you’re driving downstream, you’ll be going a little quicker than upstream, for obvious reasons.

I’ve made it out the other side…

Great. But don’t just tear off into the countryside. Immediately leaving the water you should bring your vehicle to a complete stop and wait for a moment for water to drain out and flow back into the river.

Open your doors too and let them drain. And if you’ve fitted a water blind then now’s the time to remove it. While things are draining it’s worth popping the bonnet and checking that all is okay; maybe a squirt or two of WD-40. If you don’t do this, you’ll just end up wrecking the exit and ruining the water crossing for everyone.

Once everything’s drained and you’re on your way again, give your brakes a couple of good hard hits to heat them up and dry them off.

Stuck in the water…

First thing is not to panic which is easier to write than do when your vehicle’s not moving and there’s water starting to fill the footwells. Here’s where having your recovery gear uncoiled and ready to go will pay off.

If the crossing is only fairly shallow and you’ve simply nudged up against a rock that you didn’t notice when walking the river, then you should be able to reverse up a few feet, being careful that water doesn’t make its way up the tailpipe, and then drive around the rock.

But if you’ve become properly stuck then you’ll need to switch off the engine, get out and run your winch cable to an appropriate anchor point. That’ll likely be a tree which should be wrapped in a trunk protector, something you’ll be able to take because it’s already out and ready to go, right. Perform your winch recovery and then let your vehicle drain and inspect any potential damage.

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