The risks – and how to minimise them – of paddleboarding in cold water. An appropriate article for mid-winter! I originally wrote this for the windsurfing community, but it’s totally appropriate to stand up paddleboarding.  How much do you really know about how your body reacts to cold, and how to protect it? Read on… 

If you jumped into the water in the winter without a wetsuit, you’d die of hypothermia, right? Wrong!!. What d’you mean wrongeveryone knows that hypothermia is a killer!?? Yeah, right, like everybody knows that eighty, er, or is it ninety percent of your body heat is lost through your head…. And you know that because you’ve personally stuck your head in the fridge and measured how cold it gets? Thought not. See where I’m coming from? Truth is, most paddleboarders actually don’t know diddly about the true dangers of cold water. Just a bunch of ‘facts’ that get passed down the line, like the one about 78% of statistics getting made up on the spot. Anyway, hopefully I’ve now got your attention – you may be a hardcore winter watersports dude, but chances are you don’t actually know as much about the true nature of the dangers as you thought you did. So, settle down, and prepare to learn some cool (geddit?) stuff…

Let’s start with that hypothermia issue. Fact is, even in seriously cold water it actually takes a fair old time, like 30 minutes or more, for your core temperature to drop below 35°C, the technical definition of becoming hypothermic. If you jumped into cold water without a wetsuit, either the initial ‘cold shock response’ of the body, or the loss of muscular function due to the cold will probably cause you to drown long before that. The Cold Shock Response is what kills people whose cars go into rivers in the winter, and when you hear about it on the news you wonder how the hell they didn’t manage to get out and swim to the surface, and you feel pretty confident that you’d probably have aced it had you been in that car yourself. Whereas actually, you probably wouldn’t.

The body has lots of reflex actions programmed into it for various primeval survival situations, most of which are pretty darned useful (the ability of all males to instantly turn the radio off when Justin Bieber comes on, for example), but the Cold Shock Response was clearly coded in on one of the Almighty’s off days, probably first thing on a Monday morning after a big Sunday night on the razz with Zeus and Odin. The body’s instant reaction to immersion in cold water basically involves a set of fairly severe cardiovascular, respiratory and metabolic changes, which could in worst-case circumstances kill you outright, due to the sudden massive extra load on the heart. Your pulse rate can increase by up to 50%, blood pressure increases significantly and there’s risk of irregular heart rhythm or even complete arrest. There’s head pain and disorientation due to the sudden decrease in cerebral blood flow, and some complicated stuff involving haemoglobin levels. But the really big bummer is the gasp reflex – that big involuntary intake of air, followed by your lungs burning through the oxygen at ridiculously high levels, so basically you can only hold your breath for a few seconds (if you’re actually lucky enough to have air in your lungs rather than water). Not exactly top of your list for survival strategies, right?

However, the good news is that you do acclimatise fairly quickly. As you know yourself. First time you get wet in winter water, it’s the full ‘ice creams’ and holy moley what I am doing out here? Second time, it’s nowhere near such a big deal. (And the fitter you are, the less it is of an issue anyway, for various cardiovascular reasons.) So – in the event that you do ever find yourself in a car in the river in winter, stick your head underwater for a few seconds first, resurface and recover, before you try to swim out. Seriously, it will probably save your life. And likewise, whereas obviously the problem is vastly reduced by wearing a good wetsuit, it’s still a good idea, if you’re launching out into mid winter waves, to get the first dunking over and done with while walking out through the shallows. As otherwise, if your first wipe-out of the day involves a major working in the rinse cycle, holding you under water for a fair few seconds, you might well find yourself out of breath much much quicker than normal.

Anyway, you’re not planning on being anywhere near cold water this winter without adequate protection, right?

Of course not…

But there’s always that temptation to use the short-armed summer suit for that surf session – especially seeing as they’re so damn good these days – till quite late into the season. (Although seeing as winter started aroundabout February this year, you’ve probably been in the full 5mm and hoodie for weeks before reading this!). So let’s just talk a little about how the body does cool down. Because, let’s be completely clear about this. Winter watersports are a totally different game to summer watersports – you are operating in a life-threatening environment. Here’s the big five reasons why it could ruin your day.

Winter weather tends to be more violent and unpredictable.

Cold water is harder. Due to the increased viscosity of cold water, it packs more of a punch.

It gets dark much earlier in the winter.

There are far less people around to notice if you get into trouble.

Your long-term survival chances in cold water are massively reduced.

So if you go out for an afternoon paddlesurf on a remote beach, wearing insufficient neoprene, the wind switches offshore and you lose your paddle – the stark truth is that your chances are somewhere on a par with the England football team in a penalty shoot-out. (I.e dangerously close to zero)

Now you’re nothing but a muppet if you haven’t checked and fully understood the weather forecast before you go out, told someone where you’re going, and done something about that dodgy legrope. Yet there will always be those times when the wind suddenly switches offshore or the surf gets up, or you end up on a different beach to the one you’d told the missus you were going to, and it’s amazing how the time passes without you realising when you’re out there having fun. Shit happens. But, there’s definitely one variable in the picture that you do have complete control over, and should just never be a factor in an emergency situation. There is absolutely no reason to go out in the winter with insufficient neoprene!

Because here’s the killer (in every sense). If you do find yourself in the England penalty shootout scenario, you could be talking about a long swim ashore. It does happen. Hell, I’ve had it happen to me three times now – and I’m the most careful son-of-a-bitch out there, because I know about this stuff. Yet once I managed to slice my wetsuit right open on my fin, in the mother of all wipeouts which also saw my leash break and my board disappearing off in the other direction. Now that was a scary one. Another time the wind suddenly kicked in at about 30 knots dead offshore withot any warning at all, and by the time I reached the shore it was pitch black. And then, back in 2006… Well, let’s just say I’m too embarrassed to even fess up to it. But man it taught me some lessons.

Anyway, my point is that – at some point this winter – at least one of you, maybe more, will find yourself out at sea in a scary situation. It will happen. And it might very well be you, yes, YOU. So, think about being out there. In the oggin for maybe several hours. What can you do to increase your chances of staying alive?

Firstly, even if you’re in the world’s best wetsuit, you’re still better off out of the water than in it. Water has about 24 times the thermal conductivity of air, so heat transfer from your skin to the adjacent cooler water is extremely rapid, and your skin temperature quickly drops down towards the water temperature. So if significant amounts of your skin are exposed to the water (i.e. your wetsuit leaks, you’re only in a short-arm suit or whatever), the this heat loss will reduce your ability to prevent yourself drowning long before hypothermia sets in. As said earlier, it is actually almost impossible to lose enough heat to get hypothermia in less than 30 minutes, even without a wetsuit in 5°C water. Whereas studies on swimmers in cold water have shown that swimming efficiency decreases fairly steadily, long before hypothermia becomes a factor. It becomes increasingly hard to straighten the arms, the fingers begin to splay and flex, resulting in a shorter, less efficient stroke. Eventually, you can’t continue, and that’s when drowning becomes the next item on the agenda. The ability of muscles to contract starts to decreases once the skin temperature has dropped below about 27°C, and that’ll happen after just 20 minutes in 12°C water. Your power output will decrease by about 3% for every 1°C decrease in muscle temperature. It’s down to the muscles becoming progressively less efficient as they get colder – because there is less blood flow the skin as the body cools, there is less oxygen getting to the muscles. As a result, you’re getting more anaerobic metabolism, which results in more lactic acid build-up. This is something that the arms suffer from in particular.

So, good insulation is going to make a major difference in your chances of swimming ashore after losing your board (and this is also one area where the pie-eaters are laughing. Internal insulation helps prevent heat loss too.)

There’s also the issue that it’s moving your body parts through the cold water which is making the heat loss so rapid. In 5°C water you cool down nearly 50% quicker when swimming compared to staying still. So even though the cooling rate will be considerably less in a wetsuit, the movement of water over the hands, head etc as you swim is going to mean heat loss, so if swimming to safety isn’t an easily practical option you might be better off staying put. Obviously if you’re in a black wetsuit with night just round the corner, the nearest rescue boat is many kilometres away and you can see your friends on shore high-fiving and divvying out your remaining kit between them, you might as well have a go. But if you know that you are going to be found and help is on the way, then don’t play the hero and try to swim ashore, if you’re already cold. You might just not make it.

Staying still while in the sea is not an option without buoyancy of some sort to support you though, unless you can breathe through your ears. Your best bet for buoyancy is obviously your board. If you have it, get onto it. Getting your whole body out of the water will halve the rate that you cool down, so whatever the circumstances you are better off being out of the water, no matter how cold the air temperature may be.

If you don’t have your board, then maybe you’ve got a bouyancy aid. The pros and cons of bouyancy aids for paddleboarders are not the topic for discussion here, I’ll come back to that in a future blog. Suffice to say, if you’re going a long way offshore then it makes a whole lot of sense (besides being a legal requirement!), to strap on a belt-pack PFD. So easy, and potentially, so life-saving!

But let’s say you don’t have any bouyancy. And you’ve been separated from your board. It’s a pretty unlikely situation but absolutely not impossible. It can happen, it has happened, and it will happen again.

If you don’t have any buoyancy, then the important thing to do is keep your head out of the water. Because as we all know, ten zillion percent of your body heat is lost through your head! Seriously, if you are going to try and swim ashore, an extremely important factor in determining your rate of heat loss is whether or not your head is immersed. While front crawl may be the fastest stroke for most people, it’s also going to sap your heat the quickest – significantly. If you can, do breast stroke or sidestroke. Keep your head out of the water as much as possible.

If you are getting cold, then eventually you are going to start shivering. This is the body’s natural way of trying to warm you up, but it’s not actually particularly helpful right now as it interferes with your swimming and posture, characterised by a painful aching sensation in the back and groin. But the important thing to remember is that this does NOT mean you’re becoming hypothermic. Shivering is a natural response that is initiated a long time before hypothermia becomes a factor. So don’t panic – keep swimming!

One other top tip is to make sure you are warm and well fuelled up before you go sailing. (And you know I’m not talking alcohol here.) If you find you’re getting cold, then call it a day earlier rather than later. If something goes wrong now then you are in a much more dangerous situation, as your temperature and energy stocks are already lowered.

No-one knows precisely how long you can survive in cold water. Unfortunately, ethics committees ban this sort of experiment on humans (although apparently they’re wavering about using jetskiers). There is data from actual cases of survival (a lot was generated in WWII, thanks to all the poor sods on the North Atlantic convoys who got torpedoed and then spent hours in the water before rescue, and from some of the unspeakable ‘research’ carried out by the Nazis in concentration camps). But other than perhaps producing some really outer-level figures (i.e. no-one is going to last longer than X), it’s basically all speculation. And when we bring our neoprene factor into the equation, the variables increase even further. What thickness of neoprene? Number of holes in the stitching?

Nevertheless, there is no doubt that you’re going to survive a lot longer in a decent wetsuit. So, take a good long hard look at your current winter wardrobe. How long have you had that suit? Getting a little leaky around the zip or neck now, is it? Some of those seams opening up a little? If you have even a shadow of a doubt about it, don’t even think twice about renewing it – just do it. This is the one piece of your entire windsurfing equipment armoury that will save your life – it’s not a piece of rubber, it’s an insurance policy. Modern winter wetsuits are awesome. They are super- stretchy, super-comfortable, not at all restrictive, pretty easy to get on, have amazingly funky neck seals, and they’re really warm. Some now even have built-in heating systems. You cannot give me one single good reason for not being as warm as possible while out there sailing this winter – unless you’re some kind of weirdo masochist, in which case I’m sure you can think of a whole bunch of other things to be doing with a black rubber suit that I really don’t want to know about.

Which suit is best? That depends. The horizontal dry back zip suits are still reckoned by many to be the ultimate in warmth, simply because they provide the very best neck seal, but some of the modern zen-style neck closure systems are pretty damn good and give a lot more flexibility to the suit. Just go try a bunch on – you want to get up close and personal with your life support system. This isn’t something to be buying off eBay. We’ve detailed some of the latest products from the leading brands around this feature – they’re not tests, but these are all great brands and make hot suits (in every sense). We’d be happy to recommend them.

Oh, and in case you’re still wondering, it’s temperature dependent. And it’s actually a pretty daft sort of discussion anyway, because if you’re outside in the cold in normal circumstances, of course a large percentage of your body heat is going to be lost through your head, because you’re going to be wearing a sodding great coat, thick socks and trousers. So where else is it going to be lost from? But anyway, just so’s you can put people right next time they try to baffle you with bullshit, here’s the official skinny: “About 50% of total body heat production may be lost through the unprotected head of a lightly clothed individual in an equivalent air temperature of -4°C”.

So the moral of that story is pretty clear. Wear a friggin’ hat!


Just in case you’ve read this piece through and are now thinking holy shit, I ain’t going near the sea again until at least January – let’s just be clear about things here. Winter watersports are awesome. Not just because the conditions are usually so good, but because it’s a completely different buzz. Any schmuck can get wet in the summer, but in the winter, you’re cheating mother nature. You aren’t supposed to be out there. But you are. And it feels great! Especially when you consider the alternative. Centrally heated offices filled with winter flu bugs, the midwinter blues – fuggettaboutit! Get out there and fill your lungs with some good sea air. If you’ve got a good wetsuit, and a medium sized helping of common sense (if you’re lacking on the latter, then spend more on the wetsuit!) then the worst experience you need get from winter paddleboarding is a dose of the ice creams; a tiny price to pay for the sheer joy of a good session on the water.