Safety through information not dictation
By Rob Fryer

Hazard Problem Remedy or Caution
Abrupt shelving or unstable bed Paddlers taken out of depth Check river bed beforehand
Cold water Jumping in may lead to involuntary intake of cold water & drowning. Walk in first + wet suit.
Slightly cold water. (or not so cold) Swimmers unaware of stealth chilling. Loss of movement & Drowning. Wet suit
Wide river or lake (or not-so-wide) Overestimate of ability, especially the chilling effect of cool/cold water. Drowning. Swim along the shore.
Cloudy water Jumping in leads to injury on underwater obstructions: rocks, trolleys, dead branches etc Walk in & reconnoitre swim first.
Steep banks Prevents exit Check exits first
Rock formations: especially in or upstream of them. Current may draw swimmers into underwater cavity or channel Swim downstream of rocks or follow a local swimmerís advice.
Weirs: especially large or fast ones. Plunging water draws nearby surface water down with it & hence creates an upriver surface current. Below-weir swimmers likewise carried up to weir & under. Hence swimmers trapped. Avoid.
Fast current:ie faster than you can swim. Loss of control: entrapment against obstacles, or drawn to places where no exit exists or where a lengthy swim is required to exit. Avoid, or at least be aware.
Undercurrent. Possibly dragged under water. Use backstroke: brings legs to surface
Long strong weeds Legs entangled. Swim downstream, arms only
Cramp Impaired leg movement Add buoyancy with wetsuit.
Swimming with open wound in water polluted with rats urine. Weilís Disease (Leptospirosis) Sudden onset of flu-like symptoms 7 Ė 26 days later. Secondary stage possibly fatal Get blood test & treatment before secondary stage. Acid & flowing waters safer.

Are you in good health? Just as you wouldnít swim in the sea if you were feeling a bit off, so you shouldnít swim in a river if you a feeling sickly. Are you a good swimmer? You really must be a good swimmer to go wild swimming because of the risks associated with it.
Rather than jumping into the nearest available patch of water, find a traditional swimming hole. It will be safer. Talk to local swimmers; they should know the hazards. Why not let them go in first? Follow a local swimmer into the water, if you can. Thatís my rule.
Donít swim alone. You may need someone to rescue you.
Donít swim after drinking alcohol or taking drugs. Alcohol is a substantial factor in drowning statistics.
If in any doubt always keep within your depth.
Donít swim after a heavy meal.
Select your landing point before going in. It may be impossible to get out!
Look at the surface of the water, which may indicate currents and depth. The water may take you along with it, so look where its going. Its safer if the current takes you to shallow water.
Look over the site to check for underwater obstructions. ómuch easier in clear water, hence the additional risk of swimming in cloudy water. Check the depth before jumping, yet alone diving in. The water may only be as deep for as far as you can see. Every year lots of people dive into shallow water and break their neck. You don't run quite the same risk by jumping in feet first. Better still, walk in and check the depth first. Surprisingly, even in water free of underwater obstructions you can still break your neck if you run in and do a shallow dive. It seems that because of your speed your head is pushed down.
Iíve heard of people breaking their legs or back by jumping from a bridge into shallow water, or smashing themselves on the deck of a boat passing under a bridge. Donít jump from above a bridge pier as the river is likely to be shallower there. It should (but may not) be deeper below the centre of the arches.

Weirs: Beware of swimming below weirs as the surface water often runs back upstream (the "Back tow") thus trapping the swimmer under the fall of water. This is usually only true of large weirs where there is a strong flow of water running over it. Look at the surface of the water to find out if this is the case. Give large weirs a miss anyway; just the force of the water is dangerous. Never get into the box of a box weir, you may never get out. Look out especially for a new type of weir called the anti-scour weir. The downstream sloping side of these weirs has an underwater lip which spins the water horizontally. This design prevents the water scouring the foundations of the weir, but increases the back-tow danger very considerably. Once caught in it you have little chance of escape. On the other hand, some small conventional weirs create very good plunge pools below them, Many undercurrents are not apparent from the surface. Iíve heard some horrific stories about undercurrents. All you can do is to make certain that you follow a local swimmer. If your legs do get caught in an undercurrent, you will need to raise them up, so that your whole body is in the surface layer of water. Swimming faster or perhaps backstroke may achieve this. Weirs & waterfalls can be undercut, and the force of the water can be very powerful in these places.
Weeds can trap you. They really can. I used to think that stories about getting trapped in weeds were exaggerated rubbish. However, while walking across a river one day, I found that I was wrong. Weeds can easily flow into a deep hole in a shallow river. I walked into one such hole and immediately felt the long weeds taking hold of my ankles! I was rather concerned. I could have retraced my steps, but I wanted to cross the river. I tried swimming, but didnít seem to move. Luckily I was pulled out by Harry, my Newfoundland dog. Some say that you can escape by keeping your legs still & doing breast stroke arms only. Swimming downstream may be a better way to disentangle.
Weeds can grow on the bottom of a deep lake. There is a quarry near Poole, used by the marines, where many people have drowned. The top 6ft or so is clear of weeds, and in the middle there is a pontoon, which you can swim out to. However if you do so, and then dive deeply off it, you get entangled in a dense mass of weeds growing at the bottom. Nasty.
Strong currents can drag you into all kinds of trouble. Perhaps you could be pushed against obstructions like rocks or sunken trees or worse still into an underwater cavity. Is the river in flood? This may not be obvious to a stranger, so again, ask a local. A river in spate will have a different nature and is nearly always very dangerous. Some rivers are more susceptible to flash flooding than others. For instance the Swale has been known to rise by 3 metres in just 20 minutes. Usually the first signs are a change in the water colour. It may become muddy or darker.
Cramp: You either swim within your depth, or with buoyancy (perhaps a wet suit might do.), or with a lifesaving friend, or you may drown.
weir Pike: You can get a good bite from a pike. This seems to happen when people simulate the movements of a fish.
Fish hooks & rubbish are hazards. Obviously there is a risk from sharp objects in rubbish. Wear shoes.
Boats:, especially powered craft can approach quickly & quietly and run you down. Snorkelling puts you at greater risk of being run down. The boat may not see you, and you may not see or hear the boat. A lookout from the shore might be helpful.
unforeseen circumstances: Consider the risks created by unusual or unforeseen circumstances or combinations of circumstances. Many accidents happen when your luck runs out and unusual circumstances coincide, appearing to work against you.
Rope swimgs: You might expect that all rope swings would swish you safely into deep water, but this is not always the case. Watch someone else first,& wear shoes the first time. Some swings only take you to shallow water, while for others you need a really good full swing to reach deep water.
Reservoirs: Beware of swimming downstream of a reservoir. It is nearly always colder than you might expect, because reservoirs are deep & deep water is cold.
Learners: Of course you can learn to swim in a river, but it must be much quicker, easier and safer to learn in a heated indoor pool. Non swimmers, or learners, who enter rivers are placing their lives at risk. In particular, cloudy water together with an abruptly shelving riverbed present a life threatening risk to learners and weak swimmers. This is a common combination of circumstances which you must expect to find frequently. If you enter cloudy water you must expect to be out of your depth at any moment. Learners & weak swimmers need clear shallow water.
Rescue: If you do rescue someone then get a doctor to check over the victim. Even if they appear OK after rescue it is possible to drown some time later - up to 72 hours later. A small amount of water may have entered the lungs, and this will lead to more liquid collecting there & then the victim drowning.

The sign on the right, found on the Chassezac in France, is a prime example of how a safety issue is tackled in a sensible, meaningful and effective way. Rather than simply banning swimming because of the hazard posed by rapidly changing river water levels, the local authorities in Casteljau used photographs to illustrate the danger. This contrasts sharply with the attitude of some authorities in the UK who ban swimming for unconvincing reasons (e.g. the water is cold / deep) with predictable results.