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| Health and safety in outdoor swimming and river swimming
Hypothermia and cold-shock - Outdoor swimming in cold water saps body heat. Shivering and teeth-chattering are the first stages of mild hypothermia, so get out of the water and warm up with a combination of warm, dry clothes and activity. Press-ups, star-jumps and running up a nearby hill are the quickest! Wear a wetsuit if you want to stay in for more than a quick dip. ‘Cold-shock’ is the involuntary gasp and rise in heart rate that occurs as the body enters very cold water. Test the temperature and wade in slowly unless you are already acclimatised to outdoor swimming. Jumping and diving - Always check the depth of the water, even if you visit the same spot regularly. Depths can vary and new underwater obstructions (sand, rocks, branches, rubbish) may have been brought downstream or tipped in. A broken neck from a diving accident could paralyse you for life. Cramps and solo-swimming - Swimming cramp can occur in the calf or foot and tends to be caused by overexertion, over-stretching and tiredness. Cramp is not more likely after eating but dehydration, or a poor diet in general, can make you especially prone. If you get a leg cramp, shout for help, lie on your back and paddle back to shore with your arms. Swimming alone in deep water is foolish but, if you must, wear a life jacket or trail a float behind you on a cord. Weeds - Most common in slow, warm lowland river swimming and lake swimming, weeds are quite easy to see and, while one or two aren’t such a problem, a spaghetti-like forest can entangle a swimmer’s legs. Try to avoid them. If you do encounter some, slow your swim speed right down, don’t kick or thrash, and either float on through using your arms to paddle, or turn around slowly. Blue–green algae - In lowland lake swimming, after warm, wet weather, usually in late summer, algae can multiply and a powdery, green scum (the blooms) can collect on the downwind side of a lake. It’s obvious and unpleasant and can give you a skin rash or irritate your eyes if you bathe in it, and make you sick if you swallow it. Find a part of the lake without blooms or go somewhere else. ‘Swimmer’s itch’ (cercarial dermatitis) can be caught from contact with little snails that live on the reeds around marshy lakes and stagnant ponds. It creates a temporary but sometimes intense itching sensation that can last for up to two days. It’s not common, and requires no treatment, but it’s best to avoid wallowing in the bogs when outdoor swimming! Weil’s disease - In urban areas sewers and storm drains may harbour colonies of rats whose urine may carry the bacterial infection Leptospirosis. Never swim in urban rivers, particularly canals, and be particularly cautious after heavy rains. None of the locations in this book carry any significant risk but if you are concerned about water quality cover any open wound with a waterproof plaster and keep your head (eyes, nose and throat) out of the water as much as possible. If you get flu or jaundice-like symptoms three to fourteen days after swimming in high risk water ask your doctor for a Leptospirosis test. It is simply treated with antibiotics but if left it can develop into the more serious Weil’s disease, which has been known to kill. Moving water and currents Lots of our best water moves and river swimming in and against a current can be fun, just like swimming in seaside surf. However, you generally want to avoid being taken downstream in an uncontrolled manner. Even shallow water, if it’s moving fast enough, can knock you over and carry you away. Always consider: if I do lose my footing or get swept downstream, where will I get out? Identify your emergency exits before getting in and scout around for any downstream hazards (obstructions, waterfalls or weirs).When judging flow rates remember the basics: the shallower or narrower the river bed becomes, the faster the water must flow to pass through, and vice versa. That’s why ‘still waters run deep’. Throw a stick in the water to judge flow speed and avoid anything moving faster than you can swim. In tidal estuaries there can also be counter-flows, with seawater moving in and river water moving out. In deep rivers or gorges the water in the surface layer may be flowing more slowly than the water beneath. These confused waters aren’t necessarily dangerous or outdoor swmiming – you’re not going to be sucked under – but they can be disorientating and may take you out into deeper water or close to an obstruction. You can generally feel what’s happening under the water with your feet and body. Large eddies and surface ‘simmering’ also suggest something more powerful is happening beneath. Be particularly cautious in these unpredictable waters. Currents can be especially powerful directly under large waterfalls or weirs. As with breaking waves the water can be flowing in two directions, with some water exiting from the fall downstream while some creates a ‘rip-tide’ that is circulating to the back of the fall. Semi-circular or ‘box’ weirs, which have three sides, create particularly dangerous re-circulating currents in the confined space within their walls. In a large plunge pool you’ll generally feel the currents long before you are in danger of being pulled under the waterfall but if you are foolish enough to swim into the tumult, and are taken down, it’s like being caught in a wave’s undertow. Keep calm, hold your breath, hope you don’t get dragged along a rocky bottom and wait a few seconds until you are spat out. If you live through this and want to know more about the extreme sport of river swimming in wild rivers, riding river currents then search online for river boarding, hydrospeed or whitewater sledging. Is wild-swimming dangerous? About 400 people drown every year in the UK, but only a tiny percentage of these drown while outdoor swimming. An analysis of recent annual accident data shows that of the 12 per cent of drowning victims who died while actually swimming, 7 people drowned in swimming pools, 11 in the sea, tidal pools and estuaries, and 7 in rivers, lakes, reservoirs or canals. In addition there were 8 who died swimming drunk, 30 who died through ‘jumping in’ to water and 17 who died in ‘jumping and diving accidents’. 95 per cent of all swimming drowning victims were male and many were teenagers. (Sources: Royal Society for Protection of Accidents 2002 data; River and Lake Swimming Association; Jean Perraton in Swimming Against the Stream) You can also read a little more about this at the Safe Watersports website. |
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