How do I swim outdoors safely?
Cold water shock, reading a location before entering, and the small number of rules that account for most open water deaths.
- Difficulty
- beginner
- Time
- 25 min
- Read
- 5 min
- Safety
- warning
Short answer
Enter slowly and never jump in — cold water shock in the first minute is what causes most open water drownings, and it affects strong swimmers as much as weak ones. Swim with someone, near an exit point, in a supervised or known location, and never after drinking.
Outdoor swimming has grown enormously and the risks are specific rather than general. Almost all of them concentrate in the first minute in the water and in the choice of where to get in.
Safety
Step by step
- Understand cold water shock.Below about 15°C, sudden immersion causes an involuntary gasp and around a minute of uncontrollable fast breathing. Gasping underwater is what drowns people, and it affects the fittest swimmers exactly as much. British water is below that for most of the year.
- Never jump or dive in.Enter slowly, let the water reach the chest, and wait for the breathing to settle before swimming. This single change removes most of the risk and it is the rule most often broken.
- Float if you get into trouble.On your back, head back, arms and legs out, and let the gasping pass. It takes about ninety seconds. Trying to swim through it is what turns a scare into a drowning.
- Choose a supervised or well-known spot.Lifeguarded beaches, established swimming lakes, organised groups. Unknown water hides currents, depth changes, cold layers and submerged obstructions.
- Never swim in a quarry.Flooded quarries look inviting and are among the most dangerous fresh water there is — extremely cold below the surface, very deep, steep sided, with machinery and debris underwater and no easy exit.
- Check the exit before you get in.Know exactly where and how you will get out, and that you could do it with cold hands and tired arms. A bank that was easy to slide down is often impossible to climb.
- Understand tides and currents at the coast.Rip currents pull outwards, not under. Swim parallel to the shore to get out of one rather than against it. Check tide times, and never swim where a river meets the sea.
- Avoid rivers in or after heavy rain.A river in spate is fast, cold and carries debris, and it stays dangerous for days after the rain stops. Water quality is also at its worst then.
- Never swim alone.With someone in the water, or at minimum someone watching from the bank who knows what to do. Solo swimming is the common factor in a large share of incidents.
- Be visible.A bright cap and a tow float. The tow float gives something to hold if you tire and makes you visible to boats, which cannot see a swimmer at water level.
- Get warm properly afterwards.Core temperature keeps falling after you get out — the after-drop. Dry off, dress in layers including a hat immediately, and have a warm drink. Do not drive until you are properly warm.
- Do not have a hot shower straight away.It moves cold blood from the extremities to the core too quickly and can make you feel much worse. Warm up gradually with clothes and a hot drink.
- Never swim after drinking.Alcohol impairs judgement, dulls the cold response and is present in a substantial proportion of drownings. This applies to a single drink at a barbecue by a river.
- Build up over the season.Regular exposure improves cold tolerance considerably. Someone who has swum through spring copes with water that would shock someone arriving in it for the first time.
Tips
- Float to live. On your back, head back, limbs spread, and wait ninety seconds for the gasping to pass. It is the single most useful thing to know.
- A tow float costs very little and does two jobs — visibility to boats and something to hold if you tire.
- If someone is in trouble, call 999 and ask for the coastguard, throw something that floats, and do not go in. Would-be rescuers are a significant share of drownings.
Common mistakes
- Jumping into cold water — It triggers an involuntary gasp and around a minute of uncontrollable breathing. Gasping underwater is the main cause of open water drowning and strong swimmers are affected just as much.
- Swimming in a flooded quarry — Very deep, extremely cold below the surface, steep sided with no easy exit, and often containing submerged machinery. They account for a disproportionate number of deaths each summer.
If it doesn't work
Sudden panic and gasping on entry
Cause: Cold water shock — Fix: Float on your back with limbs spread and wait for it to pass — about ninety seconds. Do not try to swim through it.
Being pulled away from the shore
Cause: Rip current — Fix: Do not swim against it. Swim parallel to the shore until out of it, then back in. Raise an arm and shout if you cannot.
Shivering violently and feeling worse after getting out
Cause: After-drop as cold blood returns to the core — Fix: Dry, dress in layers with a hat, and have a warm drink. Avoid a hot shower, and do not drive until properly warm.
Cannot get out where you got in
Cause: Exit not checked beforehand — Fix: Always identify the exit first and check you could manage it tired and cold. Move along to a shallower bank rather than fighting a steep one.
Questions people ask
What is cold water shock?
An involuntary gasp and about a minute of uncontrollable fast breathing on sudden immersion below roughly 15°C. It causes most open water drownings and affects strong swimmers equally. Enter slowly, and float on your back if it happens.
Is it safe to swim in a lake or river?
In a supervised or well-established spot, with someone else, entering slowly and with a checked exit — reasonably so. Never in a flooded quarry, never in a river after heavy rain, and never alone or after drinking.