What Lies Beneath...Off-Road Water Crossings

Caution, common sense, and a little courage are what it takes to safely bypass deep H20 on the trails.

by

Words by Jenny Sheets

Other than wheeling in extremely dry regions, water crossings are all part of off-roading. You may embrace them for all their exciting glory and bragging rights, while some of your trail-running buddies may not. Either way, crossing them on the trails is pretty much inevitable and requires a skill set to practise and perfect.

They can also be hazardous - for you and your rig - so it’s best to be prepared since they can appear unexpectedly due to seasonal changes, weather conditions and/or the nature of the region.

Get Your Rig Ready

If you have a high-clearance stock rig and only expect very shallow water crossings, you may not need to modify your rig. But if you off-road frequently, you’ll want to be prepared and try one - or all - of these suggested mods:

  • Install an extended breather kit and move your differential breathers higher up the chassis. This can prevent (but does not guarantee) water from being sucked into the housing instead of air, which can emulsify the oil.
  • Make sure your standard air intake, located usually behind the headlight, is above the deepest point of the water crossing. To successfully manage deeper crossings, consider purchasing a snorkel that relocates the air intake to the vehicle’s roofline.
  • Before attempting any water crossing, get your winch and recovery gear ready should your engine stall halfway across. Remember, wireless winch remotes will not work when submerged. If you don’t have a winch, attach a recovery or tow strap and have it accessible above the waterline.
  • Be aware of any electronic components that may be exposed to water during the crossing. ECUs, alternators, fuse boxes, and other components are often placed in locations susceptible to damage. Some may already be coated in dielectric grease or sealed from water ingress, but do diligent research on the best way to protect these systems and components.
  • Take note of the engine-driven fan position in your vehicle. If the water level reaches the fan, it may not only shatter but throw water onto many important engine components.

Assessing the Water Crossing

You’ll want to first determine if the water crossing is legal to cross and that it’s necessary to do so. If there are any restrictions, find an alternate route. But before crossing, walk through the water to consider the depth (all the way across), the strength of the current (if there’s one), hidden obstacles and the bottom. Remember, packed rocks are good, bottomless mud is bad.

Taking a few minutes to check the water level with the vehicle’s engine off will give your differential time to cool off as well, which will hopefully prevent water from getting into the housing. Also, look upstream for any obstacles that could potentially come loose.

Remember that once you start driving across, the force of the vehicle will create a high brow of water. Take this into consideration when assessing water depth and be very aware if there is a current. According to Dr. Greg Forbes, a severe weather expert of The Weather Channel, explains that even a current of 9 km/h (6 mph) “exerts the same force per unit area as air blowing at EF5 tornado wind speeds.” Bump that up to stronger currents such as river crossings flowing at 40km/h (25 mph) and you’re looking at a force of 790 mph. Don’t take the risk. If you cannot walk through the water due to the current, obstacles, or if it’s too deep, do not attempt to drive through it. Also, never underestimate the strength of a ‘mild’ current.

How to Cross Water in your Rig

No matter what your friends say, ‘never gun it into the water.’ This can be very dangerous and costly to your vehicle. You risk hydro-locking your engine, shock cooling components, and forcing water into critical parts and systems. Enthusiasts have been known to hydro lock and total their vehicles in just .3 m (1 ft) of water.

First, have everyone unbuckle their seatbelts and roll down the windows, especially if you have power windows in case you need to exit the vehicle. Then, drive slowly in and through while maintaining the pace of a swift walk. This will keep the bow wave high and water low in the engine compartment, but not too high to flood the vehicle. Drive straight ahead or slightly downstream if necessary and avoid pointing your vehicle upstream. If you have a manual transmission, never shift while in the water to avoid stalling.

If the engine does stall, don't attempt to restart it while submerged as water may enter and destroy it. Instruct everyone to safely evacuate the vehicle. Evaluate the situation, make sure the vehicle is secure, and then attempt a recovery.

Crossing water can be a real highlight on the trails, but it can also become a real hazard if caution and preparation are not taken.

Article courtesy of onX Offroad, a GPS mapping app that offers more than 985 million acres of public land and 550,000+ miles of open roads and trails to access for any adventurer travellers and off-road enthusiasts. Jenny Sheets is the copywriter and vertical marketing specialist for onX Offroad. She lives in Montana where she dirt bikes, trail runs, camps, and enjoys overlanding.

Tread Lightly Principles

Tread Lightly is a national nonprofit organization committed to outdoor recreation and land stewardship. Through training and online certifications, they help educate people on how to have fun outdoors while also taking care of the environment. The more we take care of our lands, the longer we can enjoy them. Here are a few tips as they pertain to water crossings:

  • Cross streams only at designated fording points and where the road/trail meets the water crossing.
  • In very soft terrain, go easy on the gas to avoid wheel spin, which can cause rutting.
  • Avoid sensitive habitats including living desert soils, tundra, and seasonal nesting or breeding areas.
  • Wash your vehicle before (if possible) and after to reduce the spread of invasive species.