Back to top

What went wrong: in too deep

30 January 2017

In a new series we take a closer look at 4×4 situations that went, well, not quite according to plan. And then 4×4 Mega World offers some advice to make sure you don’t make the same mistake. We kick it off with water crossings.

So there was Gunther, in a rental 4×4, in the heart of Botswana’s wild Moremi. Ahead of him was a river. Gunther consulted his GPS… and the machine said the road he must follow to reach the Khwai River community camp was indeed, straight ahead. Gunther knows there are hungry crocodiles in many Botswana rivers. So Gunther decides to forge ahead without checking the depth of the water. Upon entering the river though, the nose of the rental 4×4 alarmingly disappeared under the surface. Gunther later said the engine made a few ‘interesting sounds.’ Then stopped, dead.  So what was Gunther supposed to do? And what 4×4 accessories could have prevented such peril?

4×4 Mega World’s Kurt Brunner says:
“Firstly, water should be avoided at all costs. However, there may be situations where a water crossing is unavoidable. Here are a few reasons to rather avoid water in the first place. If the breather valves on your vehicle’s differentials are dirty, they may not operate as a one-way valve, as they should. So it is highly possible that the hot differential can suck water into it.

Electronics in many vehicles are susceptible to water damage due to their low positioning. The air intake pipe of most vehicles sits in the wheel arch so any wading where  the water level is above wheel height is risky to say the least, especially if your vehicle is not fitted with a snorkel. Entering water too fast can cause damage to the radiator fan blades. Most radiators are mounted quite simply on rubber grommets and a sudden force of water can dislodge the whole radiator. All this being said, you still won’t find me walking a water crossing if I know there are crocs and hippos around.

Take note of the opposite bank. Is there an exit track visible? Was it recently used or is it overgrown? Is the water level higher or lower than the watermark? If it’s lower, the chances are very good of a successful crossing. If no water mark is visible, then it’s a guessing game. Local motorists may know if a body of water can be crossed, or not, but don’t always bank on that info either. If you have access to many metres of tow straps and snatch straps, these can be joined and attached to the first and second vehicles. Should difficulty arise, the vehicle on the bank can simply reverse and tow the troubled vehicle out of the water. If you are satisfied that all the boxes are ticked, enter the water at a reasonable walking speed so to make a reasonable bow wave. This will naturally cause a low pressure below the engine, keeping it relatively dry, believe it or not.

The trick is to not stop or slow down as this will cause the water to push up into the engine bay and, quite possibly, result in electrical damage or failure.There are many differing opinions as to whether you should have your seatbelt on and windows open or closed. Truth be told, a seatbelt is mechanical and will detach even under-water. I keep mine on because the beep-beep sound drives me nuts otherwise. I like fresh air so my window is always slightly open. Stalling a vehicle with the exhaust under the water is no problem. Yes, water will flow into it but cannot get into the actual pistons. By restarting the engine, the exhaust gases merely push the water back out. But, should you get water into the air cleaner and beyond, then do not attempt to start the engine.

Your 4×4’s engine will make some very unpleasant noises. And then die. Happy overlanding.