So I am doing the Mont Tremblant half in June. With this cold, long winter I am concerned about the water temps in June. I happen to have issues swimming in cold water, ie cant relax and exhale when my face enters the water. So, I was wondering one, what temp to expect the water to be in MT in June and whether or not there is some legal cut-off if water temps drop below some level?
1 degree celsius. Any lower and you are on ice.
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Not if it’s salt water.
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WTC’s IM policy from what I’ve read is 52*-88* and that if temps were outside those ranges, swim would be cancelled. I assume that’s for 70.3’s also.
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I stand, blue and shivering, and corrected.
I don’t have the details on hand now, but the chart in the link matches reasonably well with the research on cold water and it’s impact on humans.
http://www.ussartf.org/cold_water_survival.htm
Three points to note.
Table is assuming no wetsuit. A wetsuit pushes your ability to survive out a bit.
Table ignores the affect of arm cooling on your ability to swim because it assumes you have a life jacket. Arm muscles losing very little temperature results in 90% strength loss causing drowning in far less than the quoted time. Related to this is the charts provision of two period ranges. First period is the end of your mental ability to self help. Aka won’t keep swimming. Resulting in death if not wearing a life jacket.
Final note is that the variation in times provided come from variation in body fat. More fat equals more survival time.
So for iron distance races with a 2 hour cut off. You are likely to have a substantial number of fatalities below 52 ~ 10C.
PS the gasp reflex you experience is called “cold shock” and is thought to kill about 25% of cold water immersed people. Repeated exposure should help alleviate the problem but resistance is not permanent or long lasting.
Stay safe.
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Haven’t done MT but am signed up this year. Last year’s athlete guide says the water is usually about 65 degrees F. Although it’s been very cold in Eastern North America, I’d expect the weather conditions during the summer to have a lot more to do with surface water temps than the spring. I can’t imagine that the temps would be below low 60s if that’s the historical norm. If the minimum is 52 there is zero chance the swim won’t be held. Personally I’d rather have the water 65 than 77 so I don’t overheat in the wetsuit, although I’d be just as happy if it doesn’t get any colder than that… but if it does I’ll deal.
The more you practice swimming in cold water the more tolerance you’re likely to build up to it, I believe booties & a hood are legal if you need them.
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coldest I ever swam in was in the mid-low 50’s in Northern Ontario. The organizers cut the swim from 1500 down to 400, and it was still cold. However, it is doable if you are geared up for it, a regular long sleeve wetsuit and neoprene cap should be sufficient. You may also want to vaseline your feet and hands.
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A good working rule of thumb that I use is (Water Temp F) + (Air Temp F) = 100* or more. So if it’s 45F degrees out, but the water temp is 58F, that equals 103, so swim is on! The coldest water temp I personally have ever swam in was 55F, and that was as cold as I would want to push it for myself.
If you have a venue to swim outdoors where you can acclimate to the water temps as they lower over a period of weeks, then you could potentially swim in water temps of low 40s or even high 30s, but at these temps, you’re really pushing your luck from a safety perspective.
Bottom line, know thyself. If you’re used to swimming in 75F water and you jump into 50F water for a race, you may not survive the swim. I’m not talking DNF, I’m talking DOA. Use some common sense.
My $0.02
Brian
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This is what I worry about, being one of the 25% 
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Haven’t done MT but am signed up this year. Last year’s athlete guide says the water is usually about 65 degrees F. Although it’s been very cold in Eastern North America, I’d expect the weather conditions during the summer to have a lot more to do with surface water temps than the spring. I can’t imagine that the temps would be below low 60s if that’s the historical norm. If the minimum is 52 there is zero chance the swim won’t be held. Personally I’d rather have the water 65 than 77 so I don’t overheat in the wetsuit, although I’d be just as happy if it doesn’t get any colder than that… but if it does I’ll deal.
The more you practice swimming in cold water the more tolerance you’re likely to build up to it, I believe booties & a hood are legal if you need them.
was that 65F for the half in june or the full in aug?
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4degC if it’s fresh water (that’s the point at which water is at its highest density. Therefore you need to swim at the bottom of the lake where it will be slightly warmer than the surface . The water at the top will be closer to freezing and that is too cold for swim races :-). also swimming though 0degC water will of course run the risk of hitting chunks of ice and that is known to kill any chance of a PB.
Interestingly, water is the only liquid (that I know of) that has its highest density at a temperature above its freezing point. Other liquids just get more and more dense as they approach freezing point.
Water also continues to expand (and therefore reduces its density) as it freezes, which is why ice floats. It also explains why the frozen water in the Arctic gets all those pressure ridges. The ice expands so much that it eventually rises up and buckles, a making dog sledding a pain in the butt!
Sea water freezes about -4degC from memory. (not sure when it reaches its highest density however). As sea ice gets colder and colder, the fresh water in it expands, an actually squeezes the salt out of it. The salt will fall out of sea ice in streams. Very cool to watch actually.
I don’t have the details on hand now, but the chart in the link matches reasonably well with the research on cold water and it’s impact on humans.
http://www.ussartf.org/cold_water_survival.htm
Three points to note.
Table is assuming no wetsuit. A wetsuit pushes your ability to survive out a bit.
Table ignores the affect of arm cooling on your ability to swim because it assumes you have a life jacket. Arm muscles losing very little temperature results in 90% strength loss causing drowning in far less than the quoted time. Related to this is the charts provision of two period ranges. First period is the end of your mental ability to self help. Aka won’t keep swimming. Resulting in death if not wearing a life jacket.
Final note is that the variation in times provided come from variation in body fat. More fat equals more survival time.
So for iron distance races with a 2 hour cut off. You are likely to have a substantial number of fatalities below 52 ~ 10C.
PS the gasp reflex you experience is called “cold shock” and is thought to kill about 25% of cold water immersed people. Repeated exposure should help alleviate the problem but resistance is not permanent or long lasting.
Stay safe.
Good article… If this were adjusted for someone in a wetsuit, what would you think the graph would look like? I’d estimate 15 to 20 degree variance, but that’s just a guess from someone without any science behind it…
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So I am doing the Mont Tremblant half in June. With this cold, long winter I am concerned about the water temps in June. I happen to have issues swimming in cold water, ie** cant relax and exhale when my face enters the water.** So, I was wondering one, what temp to expect the water to be in MT in June and whether or not there is some legal cut-off if water temps drop below some level?
Just putting this out there, do you do a full immersion of your head (and body) before race start? I’ve had some luck with that.
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That was the temperature listed in the athlete’s guide for the full in August.
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That was the temperature listed in the athlete’s guide for the full in August.
That’s what Iam worried about, 65F in August means what in June?
Yes I have done that and to some extent it has helped. Just not sure what the water temp was at the time and I am concerned that the half in June in mt will be colder than anything I experienced thus far.
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I think you should relax–you’ll be fine. I did the half last June and the water temp was 64 degrees. Also, the water is clear and with the wave starts it is generally less chaotic than other WTC races.
You have the chance to warm-up before the race and you should do so. Get in and get your face wet and get the gasp reflex out of the way. Also this lets some water into your wetsuit where it will warm up a bit. Consider wearing a second swim cap or a neoprene hat under your swim cap. You might even consider wearing booties if they allow it.
I’ve done a number of pretty cold swims. Last year at Lake Tahoe the air was below freezing and the water temp around 62 degrees but by splashing my face before I jumped in and by swimming slowly at the start I actually had one of my better swims. I think starting slowly is a good tip as one of the issues in cold water is hyper-ventilating and panicing a bit. Go easy for the first 2-5 minutes and when you feel settled you can up the pace.
BTW, I did the 2005 ITU LC Worlds and it was 51 degrees in the water. they shortened the swim from 4000 to 3000 meters as a result. It was a tough swim but doable. At 64 degrees or the liekly temp you’ll face at MT, you should have an enjoyable swim. Maintain a positive attitude and have fun!!!
Honestly I think you’re hyper focusing on something that is easily overcome with a bit of prep and forethought. Have you considered swimming heads up for the first bit and dipping your face in a bit at a time until you’re accustomed to the water temp?
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What’s a swimming head?
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