Defensive Driving

Water Crossing

Water Crossing

Crossing a body of water is not something one does by choice in their 4WD but such a situation may arise. With a clear understanding that this course of travel may be necessary, all water crossings deserve more than a cursory glance

water crossing

Attitude

While the water’s surface may look calm, you may find in fact the reverse – under the calm serene surface may lie boulders, holes, logs, mud or even bottomless sand that you would not drive over if you had seen it beforehand.  If that sounds ridiculous, then why would driving into water without thoroughly checking out the terrain be any different than driving without any vision of the terrain?  If you could see a surface clearly and you could see it was rough you would stop the vehicle and inspect the terrain at closer quarters and choose a path before returning to your vehicle to negotiate the smoothest most workable path.  So why is it that we don’t see the need to look carefully at water crossings? Hence, the first rule of thumb is – do not drive into any water without thoroughly checking out the terrain.

On TV and in magazines, it always looks such fun to have the water washing over the 4WD but what is not shown is the cost and the inconvenience to the owner following such activities.   A small amount of water ingested into the engine can be the cause for a very expensive engine rebuild after the recovery, which will be after the unplanned night out in the bush.

A seemingly logical reason for most to not check the water may be because it is cold or dirty.  Or maybe you have the belief that there is something lurking in the water. Well if you are not prepared to check out the water before hand and you get stuck then you will have a much longer association with that cold dirty or mysterious resident of the water.

When stuck you have to get out of your vehicle and walk out!   Now, isn’t this just the thing you had wanted to avoid along with the bonus of having water in the car as well!!!

Approach                          

A thorough inspection of the water area is required before proceeding with a crossing.   A long dead branch can assist with finding the soft spots, the depth of the tracks and the height of the ground in between the tracks. The high ground in the middle of the track as well as sticks or rocks can catch out the best drivers that do not look.

Take a few minutes to prepare for the crossing……. Assuming you have the recovery equipment and the working knowledge of how to use it correctly, attach your towing device and secure it up out of the way. This needs to be attached to a secure tow point, not to be confused with the manufacturer’s tie down points used to ship the vehicle.   This makes it easy to reach if a recovery is required.

We often joke about getting the passenger to check the depth but in reality it will be the driver who will be navigating the under water obstacles and will have to take the responsibility for the resultant success or failure of the crossing.

There are three distinct areas that need to be assessed – the entry, the crossing, and the exit.

Dropping down an embankment can be exhilarating but what goes in should come out, so check out the entry and exit angle of your vehicle then make the entry and exit driveable. Remove the loose items that could obstruct any under body components and consequently make your exit hazardous.

Rocks are often easy to move in the water due to the effects of buoyancy and you will find that a few minutes spent moving a rock or three will make the crossing much more reliable.

The Depth

Check under the bonnet of your off road capable vehicle (if you haven’t already) to establish where the air intake is positioned.  If the path chosen is flat then there should be no difficulty if the water level is not above the bumper bar and the speed is kept to a walking pace with no stops.

If the water level is above the bumper bar covering headlights or above then a snorkel is advisable hopefully fitted and sealed correctly.  Without a snorkel the distance that can be travelled at these depths is limited.  A heavy piece of plastic or purpose made tarp wrapped over the bonnet will allow for some deep fording.  Be careful not to get too carried away with this method and think about what is happening under the bonnet for the water not to get into the air intake. Slow too much or stop and all will become clear and very wet.

Your viscous fan or electric cooling fan will disengage if allowed to cool and gearboxes, transfer cases and differentials will not suck in water if the casings are cool.  So your time spent picking, marking and preparing the path will also allow for the vehicle componentry to cool reducing the risk of water being sucked into the vacuum created by the fast cooled air space in the drive line.

Most makes of off road capable vehicles have extensions fitted to the breathers so that the valve is under the bonnet for front and rear differentials and both transfer case and gearbox.

The Crossing

Always expect to have water in your vehicle and then you will not be disappointed when this happens, as it will inevitably occur.  Where possible move items above possible water levels.  With the calm and aware approach check that the front hubs have been engaged.  Low range is selected with first or second gear engaged.

Don’t forget the seat belts and remember two hands on the wheel will not only keep you balanced but may stop the impulse to change gears. and tuck that left foot under the clutch pedal!

When you are prepared for the crossing and you have decided its time, remind yourself, not to depress the clutch once in the water (water can enter between the pressure plate and the clutch plate if used under water).  This is what causes the clutch to slip when you reach the opposite bank and wonder why your vehicle slides gracefully back into the water with the engine making sounds like it should be going forward.

So, we have it all together.  We have the path marked, we have the vehicle prepared and we are prepared, so off we go ……….

Now keep your eyes on the path, keep those engine revs constant feel the wheels grip and allow the vehicle to cruise to the opposite bank, and with the same steady throttle ease the vehicle out onto the bank.  Keep the engine running and allow the water to escape out of the doors.  A word of caution your brakes are next to useless so if you have more hills, to ascend going up might be “no problem” but going down may make the water crossing quite feeble by comparison.
Enjoying our environment and not Destroying our heritage relates to Enjoy the recreation and don’t Destroy the vehicle!

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