Over the years, rally competitors have built up a body of knowledge about tackling fords, and I'm happy to pass some of this on. These notes apply to any ford where the water level is likely to be above the car's sill.

i) Type of vehicle.

You probably don't have too much choice about this, but needless to say a high 4x4 is inherently more capable than a Lotus Elise of tackling two feet of fast flowing river. If you've got a normal family saloon, use that but accept its limitations - it's more of a challenge if your equipment is not too macho. A diesel engine is better if possible because compression ignition does not cut out when the electrics get wet, so the car keeps going. Also bear in mind that cars with flat (or 'boxer') engines, such as Subaru's, are more vulnerable, since their spark plugs are low set.

ii) Equipment and preparation.

Here are some things you should do or carry:

Waterproof the electrics. Modern cars have pretty good waterproofing as standard, but if you've an older car you should properly insulate the sparking plugs, distributor, etc. Old-time rallyists use to use a rubber glove to seal the distributor. Don't make it wholly airtight or you may have moisture condensation inside the distributor.

Towing eyes. If your car hasn't already got one (most modern cars do have), and you're serious, fit a front and rear towing eye. Mark their location with tape higher up on the bodywork, so you can find them under water.

Exhaust extension. Water up the chuff can have serious complications (see below), so if you're dead keen to try the deep stuff, get a length of hosepipe that will slip over your tailpipe, and is long enough to reach above your boot lid (I hope you won't be trying anything deeper than that!) Fit this immediately before entering any particularly nasty ford, fixing to tailpipe with a jubilee clip and to the rear window with tank tape. Take it off afterwards, as it's not good for the car, the hosepipe or you to run along the road with it in place. Of course, if you're an absolute nutter, you'll get your car (or more probably 4x4) equipped with a proper (expensive) snorkel. But I'm talking about DIY stuff here.

Air Intake Extension. Some cars have very vulnerable air intakes. The pressure of the exhaust is often sufficient to hold back the water as long you keep the revs up, but the air intake, especially if you have a turbo, sucks in hard. Even when you're within your depth bits of soggy paper air filter can be a problem for the carb.  The owner of a recent model Alfa Romeo asked his dealer where the air intake was on his car. The mechanic pointed out two customers cars sitting in the yard with hydraulicked engines and said that the air intake is inside the front wheelarch! It's vital therefore that you know where your air intake is so that you can asses the fording capabilities of your car.  Even 4x4s are not all exempt from these problems. There have recently been items in the national press to the effect that the BMW X-5 has air intakes that can easily suck in water. BMW refuse warranty claims for hydraulicked engines on the grounds that their vehicle is not supposed to be driven through fords! Check your car (and dealer) for your own situation.

WD40. Always take at least a couple of cans (the second one for number two ford of the day, having left the first can at number one). This magic stuff works wonders, both at keeping your car's electrics going while wet, and at getting them going again after they've stopped. Spray liberally on all ignition electrics before entering any dodgy ford.

Radiator board. Water being forced by forward movement through the radiator on to the fan is a major cause of problems. The fan pressure-sprays everything under the bonnet, greatly increasing the risk of engine cut-out; while in certain conditions it can act under water like a ship's propeller and pull itself bodily forward, slicing into the radiator. A rally dodge to prevent water inrush is to fix a board in front of the radiator - a sheet of cardboard from a box will do, held in place by cable ties. Again, put this on and take it off before and after each ford.

Long tow-rope. Well, it's better to be prepared for the worst. Best to have one with a hook that can easily be fixed to the towing eye, without a lot of blind fiddling about under water. Real pessimists can fasten it to the eye in advance, looping it up and taping or cable-tying it to the front of the car. This is a better idea if you haven't got a towing eye, as finding a strong enough towing place under the front of the car is a wet business if it's in a foot of water.

Wellies or waders. Not so much to get you out of trouble - if you're stalled in mid-stream it's probably too late for that - as to enable you to recce the ford before you launch yourself into it.

iii) Tackling the ford.

Prepare the car. If the ford justifies it, fit exhaust extension, radiator board and tow rope. Spray liberally with WD40 anyway, for all but the weediest watersplashes.

Recce on foot. If there's a footbridge, have a look from that as well as from both sides. If you've got them, don wellies or waders and wade in, looking for holes, rocks and the shallowest route - in the case of gravel fords, this is often to one side, as generations of users have worn a big hole in the middle. Remember the adage, still water runs deep. Make sure that the exit ramp isn't too steep for your vehicle, and doesn't have a big step. Important note: don't walk into fast flowing water where you can't see the bottom, or where it's more that a foot or so deep. Water is immensely powerful and even two or three feet of strong current will drag a big man downstream. Beware invisible holes!

Leave a member of your party on dry land if possible. Let them walk across the footbridge. They can also take the pictures for the album - don't forget to send us one!

Drive slowly but steadily through the ford at sufficient speed to create a bow wave (below). Stay in your lowest forward gear, keeping engine revs fairly high, by slipping the clutch if necessary - try and make sure that exhaust pressure is kept high enough to stop water flowing back up the tailpipe. DO NOT REVERSE, especially if the tailpipe is under water.

If you feel the car being lifted by the water, open the doors immediately! You and the car interior will be wet anyway before you're back on land, and retrieving a car that's floated downstream is VERY expensive, not to mention the embarrassment of seeing your picture in the local rag after the Fire Brigade have tipped them off.

iv) If you stall...

DON'T try to restart the engine if there is any chance that water has run up the exhaust pipe. If water has passed through the exhaust ports into the cylinders and combustion chambers, the engine may fly into pieces the moment you try to restart it. This is because the water cannot be compressed and has nowhere else to go; it's called "hydraulicking". (It can also happen if you roll a car and the sump oil runs past the pistons into the upper cylinders.) See below for procedure.

Use the starter motor to pull the car out, if possible. Remove the spark plugs (as this makes the starter motor's work much easier and also obviates the risk of hydraulicking - sorry, but you're not getting out of this with dry feet). Put some sort of bung in the plug holes to stop water getting into them (screwed up paper, if you've nothing else). Engage first gear, let clutch out, and turn ignition key. I hope your battery's in good nick.

If all else fails, it's heave ho by multiple bods (using the long tow rope), or a tractor pull from the farmer next door (who is probably well used to this, knows exactly how to do it, and has a tariff that makes Porsche service bills look reasonable - so don't feel shy about asking). There are good arguments for going fording in pairs.

Back on dry land:
- Clear water from engine. Still don't restart the engine until you've taken the spark plugs out, turned over the starter and cleared any water from the upper cylinders.
- Dry out all electrics with absorbent cloth and liberal use of WD40. Beware condensation in distributor.
- Clear water from sump. This is not very likely unless the car has been standing for a fair time or is in very deep water, as the only two ways water can get into the sump are by percolating down the cylinder bores (very slow unless your engine is seriously worn), or down the filler (which presumably has its lid on). Check to see if the dipstick level is higher than expected (not so easy to judge if it's a while since you last checked your oil). If you suspect or fear possible water in the sump, let the car stand on level ground for about ten minutes (assuming the oil is still warm), then remove the sump drain plug. Any water should by then have sunk to the bottom (being denser than oil), and flow out. Replace the plug as soon as pure oil emerges.

v) Tidal roads

Check the tide tables. You can access the Admiralty tables by hotlink from www.wetroads.co.uk. Local high tide times are also available near most tidal roads. Don't get caught, or leave your car where it'll be under water in an hour. Don't take a chance on beating the tide - lots of good cars have been lost that way.
Don't go through salt water! I don't recommend going through any tidal ford when there is any water in it, or through any other sea water, as you can never completely rinse it away afterwards with fresh water, especially from all the underside nooks and crannies. If you do do so, the best solution is a thorough steam clean on a ramp; next best, hose the car down thoroughly as soon as you can, especially the underside.

vi) Night-time fording

Take a torch! (image sent in of Standon Ford by Graham Tabor and Dave Taylor)

vii) Make sure you are covered!