How to drive through deep water

With the recent floods in South Africa, there are undoubtedly motorists who have been caught in stressful situations.

Flooded roads are especially dangerous for the inexperienced driver, as most passenger vehicles start floating in 300mm of water, while 600mm can “carry away even some heavy-duty vehicles,” according to Nissan Terra Chief Vehicle Engineer, Hironori Awano.

It is therefore imperative to know how to navigate deep waters safely to make sure you and your vehicle are not put in more danger.

Know your maximum water wading depth

The maximum water wading depth for a car is the deepest water it can traverse safely without damaging onboard components.

The depth rating differs from vehicle to vehicle, and it is usually determined by where vulnerable systems such as air intakes and distributors are located.

The maximum water wading depth of some of South Africa’s favourite cars are as follows:

• VW Polo – 106-120mm (No higher than the lower edge of the vehicle body)
• BMW 3 Series – 250mm
• Renault Duster – 350mm 
• Jaguar I-Pace – 500mm 
• Toyota Hilux – 700mm
• Ford Everest – 800mm 

Knowing the maximum water wading depth of a vehicle allows you to accurately gauge whether it will be able to safely cross a flooded road.

Check for debris and irregularities

Before going through a flooded area, carefully check for any debris or irregularities in the water that might pose a danger to a car, and find the best route that avoids these.

After driving through the area, check the vehicle’s engine bay and undercarriage for any irregularities or debris that might have gotten stuck before continuing with the journey.

Ease into the water at 3km/h

If you must traverse a flooded road or area, it is recommended to ease into the water no faster than 3km/h.

This reduces the chance of liquid entering the engine and damaging critical parts due to a “bow wave” that forms at the front of the vehicle as soon as it touches the water.

Keep your momentum

Keep a slow and constant speed and maintain pressure on the accelerator pedal when you are crossing deep waters. This prevents liquid from flooding the engine through the exhaust pipe.

Additionally, never stop in the middle of a flooded area unless there is absolutely no other option, as this makes it even easier for the car to be picked up and carried away.

One car at a time

Only have one vehicle drive through a flooded area at a time.

This is so that no one will be forced to go around or stop in the middle of the area if a vehicle ahead stalls or gets stuck.