Water crossings are the crème de la crème of 4WD challenges but a real nightmare if you don’t know what you’re doing. Use these tools and techniques to make it through safely. By Nell Hofmeyr
Unless you’re an experienced off-roader with a taste for adventure, you probably want to avoid water crossings on your travels. They are to blame for innumerable tears and plans gone awry in Africa’s remote regions and, in the worst cases, costly vehicle damage.
For who don’t know how to plan, approach and execute a water crossing, 4×4 training expert and facilitator Andre Botha has some sage advice. Read on to learn what steps you can take to stay out of deep water (and deep trouble!).
If you can’t walk it, don’t drive it
Commit this rule to memory! The only way to determine the safety of a water crossing is to walk it. If you struggle to wade through the water, you bet your vehicle will battle to make it across too.
The first step is to figure out if the water is flowing or still-standing. This is vital information because it tells you more about the ground surface below. “Flowing water means that muddy sediment is kept afloat and moving with the stream, leaving only pebbles and small rocks on the riverbed. With still-standing water, the sediment has already sunk to the bottom, which makes crossing the water far more challenging,” warns Andre.
T4A tip: If the water is still-standing, inflate your tyres to 2 Bar+ to see your vehicle over the muddy surface.
The strength of the flow is equally important. If the water is flowing too rapidly to walk through, do not attempt the crossing. Fast rapids are unpredictable and can easily leave your vehicle stranded. Rather play it safe and find an alternative route.
Next, you need to determine your entry and exit points and measure the depth of the water from one point to the other. But how deep is too deep to drive? “Anything deeper than knee-height is risky,” cautions Andre. Alternatively, you can use wheel height as an estimate, keeping in mind that the water should generally not be deeper than your front wheel arches.
Pay attention to any concealed obstacles beneath the water. The last thing you want is a jagged rock slashing your tyre walls. “Look out for any rocks, branches, holes or other obstructions. Never wade barefoot and always use a walking stick to help you determine depth.”
“The biggest mistakes people make is failing to walk the crossing and underestimating the force of flowing water. Most casualties occur when water gets into the engines via the air intakes or sucked into the differentials.”
Also read: Mud driving tips for overlanders
Prepare your vehicle
The location of your vehicle’s air intake will affect how your vehicle handles the water crossing. Its position differs across brands meaning that one vehicle’s “wading depth” will likely be different to another’s. Ideally, you want to minimise the flow of water into the engine compartment as far as possible. Never attempt a crossing if the water level rises above the air intake height. A clever way to counteract this is to outfit your vehicle with a snorkel, which effectively raises your wading depth to the roof line.
Don’t wrongly assume that it gives you free reign to plunge headlong into deep water. “Be very careful about thinking a snorkel will dramatically improve your wading depth. Water can still damage your Engine Control Computer and other electronics,” Andre says.
Outfitting your vehicle with diff-breathers is one of the first modifications you should make before driving off-road, particularly if you plan to drive in water. When a hot differential comes into contact with water it cools rapidly, causing it to shrink and suck in air, or water when submerged. The water will likely travel past the oil seals and into the engine compartment.
“If you are a serious off-roader and frequently have to do water crossings, you need to lift your diff-breathers as high as possible. Make a point to have your breathers checked with every service,” he advises.
In addition, Andre recommends putting a blanket, tarpaulin, car mat or a similar barrier between your grill and radiator to lessen the flow. “Also make sure that your air conditioner is switched off so that the fan can’t run and bend due to the weight of the water and cut into the radiators,” he says.
- Loosen your safety belt and roll your windows down.
- Select low-range second gear for manual vehicles and low-range drive for automatics.
- Enter the water as slowly as possible keeping a straight line
- As your rear wheels enter the water, accelerate to a minimum 2000 rpm. This is to ensure the turbos work optimally.
- Maintain momentum right through, keeping the bow wave in front of the vehicle as you move.
In deep water
- Keep the engine running if your vehicle gets stuck
- If you can’t reverse in your tracks, have another vehicle assist with a snatch strap recovery
- Don’t waste time if the flow picks up or your vehicle sinks further into trouble. “If you’ve pushed the boundaries, save yourself and the passengers and exit the vehicle ASAP!”
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Water crossings in Africa
Water crossings appear all over Africa but some of the deepest and most dangerous are to be found in Moremi and Lesotho. “A lot of damage to vehicles is caused by the numerous deep water crossings in the Okavango. In this region, you must consult park officials, locals and fellow off-roaders on the depth and flow of these crossings, keeping in mind that this is crocodile and hippo habitat.
“Lesotho also has plenty of water crossings and travellers need to know that flash floods and fast-flowing rivers are a reality here. If the crossings are too deep, rather wait it out as the rivers flush down quickly and you will be able to cross safely within a few hours.”
For T4A co-owner Johann Groenewald’s take on how to handle water crossings, check out these useful tips.
Where have you encountered the deepest water crossings in Africa? Share your insights with your fellow T4A travellers in the comments below.