The Dirty Dozen: Surviving Deep Water Crossings.

In Motorcycle Riding Techniques by Julian2 Comments

Crossing rivers and riding in water is one of the regular features of off road riding. For some it’s an exciting thing and a chance to pit your skills against the unknown, for others it sends a chill running down the spine like a letter for the tax office.

Water crossing is easy

But whether you are on a big adventure bruiser or a lightweight trail bike, at some point you are going to come up against a deep expanse of the wet stuff that you want to cross. Doing it right can be the difference between a brief diversion in a perfect day and a hydrauliced engine and hours spent with the spanners.

Water crossing on a dirtbike

So with this in mind, here’s our guide to being like Adele – you know – saying hello from the other side …

1. Consider the options

OK, so before we get into the specifics of how you forge through the waves, you need to consider whether that is an absolute necessity. We’re not talking overthinking a 6 inch deep creek, but once you are looking at an expanse of river that could drown your bike, then a brief look at the map to see whether there is a bridge relatively close is a smart move. Pumping water out of your crank is not.

River crossing in Vietnam

It’s worth having a think too as to whether you have rerouted those breather tubes from your carb, or you never really got round to it …

2. Worst case scenario

BMW adventure motorcycle stuck in a river

So lets assume that you need to cross the water, but before you do it’s good to know that if things do go ‘tits up’ you are actually capable of returning your bike to running after the disaster. Do you have a plug spanner? How much of the bike do you have to remove to reach the plug? Are there enough of you to up-end the bike to get the water out? These things matter and if you don’t have both the tools and the knowledge to solve the problem you are about to potentially cause, better think again.

It is not the responsibility of the other riders to fix your bike – sure they will probably help but don’t drown it and then stand there expecting others to mend your scoot. Clear?

3. Don’t Assume

It can be foolish to assume that because you’ve made a crossing in this location hundreds of times before that it’s safe – 4 x 4s tend to use the same trails as bikes and they can change the river bed considerably, from moving about rocks to digging massive holes where there was previously safe going. Ignore this basic reality and you may well disappear down a hidden sink hole!

Deep river crossing on an adventure motorcycle

4. Stop, look and maybe walk

It’s a sensible thing to stop before a big crossing and have a look at what you are going to do. It’s a chance for your engine to cool down – again a good thing if you are about to immerse it in really cold water – and it gives you a chance to discuss strategies with you riding buddies.

Water crossing in Cambodia

Have a good look at the water – disturbed water indicates shallower areas, whereas still waters do indeed run deep.

If there is a doubt about the depth, one of you is going to have to walk across, ideally using a stick to assess the depth ahead of you. Yes that guy will get his boots wet, but it’s better than losing a bike in a plunge pool. And if it’s too deep to ride, you may all end up pushing your bike through, or in extreme cases, carrying it!

5. Where’s the intake?

Once you know how deep the water is, you can assess how successful this mission is going to be! If it’s deeper than the lowest air intake on one of the bikes in the group, then you may need to look at a plan b.

Water crossing in Morocco

Bikes like the reverse cylinder WRFs or the upside-down motor Husaberg can take stupidly beep water as the intake is high under the tank. But if you are riding with a guy on a tiny little CRF230, his bike is going to be the deciding factor …

In general, bikes with top loading air filters tend to be better at keeping out the water than the side loaders, but all have a weakness in the drain holes at the base of the air box. Blocking these just before you enter the wet stuff may buy you a few seconds, but not much.

6. Plan your route

River crossing in Vietnam

OK so you are going to go for it, so you need to think positive and visualise where you are heading. If you are the first one through, then your route will decide where everybody else goes, so don’t just plough into the water with no idea where you are going or where you plan to exit. Be prepare to change slightly if something throws you off course, but generally try to stick to the plan.


So all you have to do is enjoy the ride!

We run the best motorcycle adventures across Asia – from traversing the winding mountain roads on a Royal Enfield in the Himalayas to bashing through the jungle on a dirt bike in  Vietnam. It’s what we do, and we do it very well.

7. Beware the slime

Crossing rivers that run over raised causeways or through concrete culverts may look much easier than fighting your way across rocks and mud, but in reality this may not be true.

Look out for slime whilst crossing shallow water

That shallow crossing that looks so innocuous has been cultivating a thick layer of algae that is slimier than a politician on polling day. Concrete crossings tend to cause really nasty accidents as once the wheels gives way, you smack down onto the hard stuff and your bike will suffer as much as you.

8. Always start upstream if possible

River crossing on a Suzuki

All rivers will have a current in one direction, and no matter how slow it may look, it will affect the progress of your bike. If there id no obvious route already showing, starting on the upstream side of the entry point will allow you to be swept sideways during your crossing and still stand a chance of reaching your exit point. Start downstream and you are as stuffed as a Christmas turkey.

Of course the safest way to cross any water is to follow the line of the guy who is already on the other side. Down there for dancing, up here for thinking!

9. Straight and sharpish

When you enter the water, you want to be going fast enough to create a good bow wave ahead of you, that will effectively lower the water level round your air box. You also want to be going straight to increase the possibility of success.

Laia Sanz (KTM Images)

However cool it might appear to be to enter the water at 40 mph on the back wheel and mono it through the waves, you are not that guy and it will go wrong – fact.

9. Revs up and cover the clutch

Typically we are looking at crossing between 5 and 10 mph in first or second gear, and ideally not changing gear mid-stream. Keep the revs medium high and be prepared to slip the clutch a bit to maintain momentum, but without spinning the wheels. With strokers the engine note tends to get deeper as the water gets deeper, but don’t panic, keep the revs up and the movement forward.

River crossing in Laos

10. Stand and deliver

We are big advocates of almost constant standing on the trails and in rivers it’s much the same. A low centre of gravity will be your friend here as much as in deep sand, and it will allow you to have a good view into the water.  It’s the best position every time.

Stand whilst river crossing to lower the center of gravity

But if you are not confident standing, by all means stay sat but try to keep your feet up, and putting them down will vastly affect your progress and direction like a set of size 10 rudders. Dab if you need to, but then get them pinkies back up and out of the way

11. In emergency, press button

Kill the engine quickly if you drop the bike in a river

With the best planning in the world, things can go wrong. If you get the distinct feeling that you and the bike are heading for an underwater moment, try to kill the engine before you are submerged. Your motor is gulping down air in large amounts, so if there is no air left, it will gulp water and then come to a nasty stop. If you don’t kill the motor, then you can do lots of damage as it tries to compress the plainly incompressible water – bad news.

Once you’ve found your bearings, try to get the bike up as quickly as you can. On an adventure bike this may require a mate, but you will have to wait some time for the laughter to subside …

Push the bike to safety, ideally on the far side so you don’t have to do it again. Have a smoke, have a swear and watch your mates follow your mistake!

12. Bail out, dry out, start out!

If you have drowned your bike, then getting the water out without further damage is now the priority.

Do not touch that starter, because if the motor is indeed full of water, you will mash the internals very quickly.

Dry the engine before attempting another river crossing

Although it will vary between bikes as to how exactly how time-consuming this will be, essentially you are going to want to remove the plug or plugs, remove the air filter and using either the kicker or electric start, pump the water free from the combustion chamber. If it’s easy to remove the pipe as on a stroker, this can speed the process, Similarly, on a lighter bike, standing the bike on it’s back wheel or even totally inverting it – after removing the tank – will add gravity into the mix.

If you have a carburetor, you are going to need to drain the floatbowl also.

Dry the filter and any inlet tracts you can get to, and ensure the plug is cleaned, re-gapped and totally dry too.

Going deep on a river crossing

Once it’s all out, restarting may take a while, so don’t be in a rush. On a thumper, you are definitely looking at a full oil change after a drowning, where as on a stroker, the gearbox oil should be isolated and hopefully unaffected – check for any milkiness in the oil at the end of the day and change if necessary.

Water crossing in North WAles

If you did however survive the crossing upright and relatively dry, keep the revs up once you reach the other side. If you are waiting for your mates, park the bike so any water in the base of the air box drains out while you are waiting, and of course laughing when they fall beneath the water.

River crossing in the Welsh 2 Day Enduro

So that’s about it – deep-water crossings can now be embraced with enthusiasm rather than abject dread – can’t they?

Have you got any water crossing tip that we need to know about? Let us know and share the knowledge …

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Digiprove sealCopyright secured by Digiprove © 2017 Toby Jacobs
Acknowledgements: KTM Images, various


  1. Recently, riding my 20 something year old TDM850 down a west beach for 80kms or so and crossing a number of streams on the way, that spread out wide across the beach, causing mostly hard pack sand.
    I got a little complacent.
    As the available hard pack sand was giving way and getting softer near the heads, standing I leaned back and kept the momentum up.
    Up ahead another stream beckoned. Welcoming a little relief from the soggy sand I pushed forward.
    By the time I saw and mentally recognised this was not a stream, but tidal pools in the soft sand it was too late!
    Seeing multiple smallish holes, I dropped a quick gear and went for it.
    Just before I hit the first hole I realised in my way there was a green coloured pool at the far side.
    F@$€#!!! (Oh bother)
    Nothing I could do. Kept the throttle wide and hoped for the best.
    To my total amazement, I actually made it across this green goblin. Only to have my bike die amid the smaller pools on the other side.
    (This was due to old HT leads leaking HV when wet)
    A quick flick of the starter told me I’d not sucked water but no spark (air box up under the tank).
    Went to get off….. boots stuck in sand!
    Bike on it’s belly in wet sand!!!
    Got boots free and started grabbing my gear off the bike and running it to dry sand.
    By this time Johnno, laughing like a hyena arrived. Together we managed to drag the bike to safety. Not sure I’d have done it by myself. And here in lies my story. When doing these rides,
    a) have support or backup
    b) keep your spacing
    c) NEVER! Assume!!!

    1. Author

      Great story Terry – a lesson in how to fail with style!


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