Mathematical Equation

You will also get water ingress if the level is too high.

There are too many variables to apply a "formula".

If the vehicle has a diesel engine and is breathing through a snorkel it can perform better than a petrol engined vehicle as it does not have the "electrics" that a petrol engines needs.

Generally anything over about half a metre needs careful consideration.
Then you need to think how you will determine the depth. Walk the crossing?
Maybe, but what if you are in "lizard" country.
Does the submerged track run straight, or does it bend and have a drop off into deeper water. Is the submerged bed flat, or covered by rocks or boulders.

Even in a reasonably shallow river crossing, you have other variables such as water flow. Entry and exit angles.

No, I don't believe you can apply a "formula" at all.
Maybe, sit back, watch and see if someone else attempts a crossing.

Hi Debbie,

Apply the Cape formula. Come down to the water crossing in reverse, dip the wheels in the water to appear authentic and then park on the exit and await innocent tourist on the other bank. Note carefully the course the tourist takes and the depth over the bonnet. Greet them on the bank then do a U turn and cross the river in the safe zone.
Judge speed to reduce ingress or more pertinately seal your vehicle before you leave home.
Cheers
Ian@Mt Dare

I don't think there is Mathematical equation can be applied, though the late Albert Einstein or Stephen Hawkins could tell us another story.

There is definitely some Physics involved and the formula is NOT to get water into the air intake to the engine

The common sense approach is to walk the water crossing to see the depth or if thgere are obstacles and then tarp up the front of the vehicle whether it be deisel or petrol and then make sure the bow wave of the water does NOT come over the bonnet of you vehicle ................but you knwo that already, don't you...:-))

Having drowned a number of 4bies in my younger years I now stick to desert travel...lol

Cheers

Water too high +water flowing too fast X diesel no snorkel = BANG =$$$$

I do believe there is a mathematical equation for water xings.

If you get water in your engine it goes bang, this = lots of water in your car.

The cost of a new engine + the cost of water damage = lots of money, there for this is a big - in your wallet.

Water height/Axle height= Y
Length of crossing+ car care factor= Z
Base of crossing+ engine type= A (sand 5, rocks 4, mud 3, dirt 2, black top 1.) [diesel 4, petrol 3, snorkel fed diesel 2, snorkel fed petrol 1]
Precaution+ Vehicle setup= B
Approach speed-Bank Balance= X

Y + Z + A + B = X

If X is a positive value then don't bother as it will be too expensive. If X is negative the choice is yours.

In a previous time I had an FJ45 Tojo with a 155 petrol donk (simple and well sealed electrics) and we lived in the tropics. Had never heard of placing tarp trick and use to drive the Tojo straight into and through the creeks with water over the bonnet. Just luck I suppose.

Now I have a 75 series 4.5lt petrol (full of electronics) about 3 years ago went through a river crossing (tarp on) water level at the top of the underside of the front wheel arches, not a problem went through and proud as punch... what a great vehicle! However it was a different story coming back through the same crossing, after the third attempt, the engine getting wet, I said to me mates "bugger it pull me through".

Spose diesels do have something going for them.

A big thank you to everyone who answers my thread I do appreciate it and there are some very clever gentlemen out there. Thanks Guys

Regards
Debbie