Flotation

Summary:

When you fall through, a life jacket or other form of flotation dramatically reduces your risk of dying.  It looks like at least half the 53 people who died in North America during the 2013 ice season would have survived if they had flotation. If you are riding a snowmobile or ATV, sailing an ice boat or fishing, a flotation type suit is the best bet (see Note 4 below for sources). Life jackets and float coats are nearly as effective. For Skaters either a life jacket or a slightly modified pack full of dry clothes in a waterproof bag are good choices.

NOTICE:  AUTOMATIC INFLATING AND MANUAL INFLATING LIFE JACKETS  PRESENTS A SIGNIFICANT RISK OF ENTRAPMENT AND PREVENTING BREATHING IN CERTAIN SITUATIONS.  This type of lifejacket probably should not be used in thaw conditions or in enclosed vehicles.   Entrapment might occur in a plunge through thick but very weak (thawed) small grained ice.  This situation also might result in the victim not being able to breathe as a result of the considerable pressure developed by a partially filled life jacket squeezing the victim into the wall of the hole made during the plunge. As noted near the end of this page it might also be possible for a victim to be trapped in the window opening of a sinking car if the lifejacket inflates while he is exiting the vehicle.

As of today, I no longer wear an inflatable life jacket on spring ice.  Bob- 4-4-15.

 

Details: 

 Dr Giesbrecht describes the three primary risks associated with falling into cold water in the 1-10-1 Principle.  The following section looks at each stage for for water near freezing for open water and falling through an ice sheet.

Cold shock effects mostly occur in the first couple minutes of immersion. Cold shock effects vary widely depending on the circumstances and the response of the victim.  Death in this stage typically is from gasping or inhaling water or heart issues.  In open, near freezing water, without  a life-jacket Dr Giesbrecht estimates cold shock accounts for about 40% of mortality.  With a life-jacket he estimates it accounts for about 10%.

On ice where there are no waves in the water. The process of falling in is often slowed by the ice and once you are in the water you can usually support yourself to some extent on the ice sheet. Most ice users wear thick clothes which reduces the suddenness of the cooling effect.   These factors should reduce the risk of cold shock.

Swimming incapacitation occurs in 5 to 15 minutes as your mussels become too cold to let you tread water or swim to keep your mouth and nose out of the water. Your ability to grip things also goes away, making it less likely that you will be able to assist rescuers.  Without a life jacket Dr Giesbrecht estimates for victims in open water with no life jacket swiming incapacitation accounts for 60% of the mortality. With a life-jacket he estimates it is about 20%.  For victims breaking through an ice sheet without flotation, swimming incapacitation probably accounts for more than 60% of the mortality.  Cold shock is probably less likely on ice as the victim is usually in more protective clothing and the ice sheet makes it less likely the victim's head will go under the water surface. The ice sheet also often provides some support which may reduce panic.

Hypothermia typically takes an hour or more to make you unconscious so you can't keep your face out of the water. Usually death is from drowning but, if your life-jacket keeps your face out of the water, you might last another hour before your heart stops or you become unconcious and unable to keep your face out of the water.  Dr Giesbrecht estimates that death by as a result of hypothermia in open water without flotation is uncommon as the victims usually die from the effects of cold shock or swimming incapacitation long before they become hypothermic.  With flotation it accounts for 70% or more of the mortality. 

What this means is that instead of having a probable survival time of a few minutes without flotation, it is more like an hour with flotation. Any shore mounted rescue is likely to take at least half an hour.  A life-jacket dramatically improves the odds that you will be rescued rather than recovered....a much happier state of affairs for everyone involved.  Most of the people who died on the ice in the 2013 season probably would have lived if they had flotation. If everyone carried ice claws and throw ropes, the numbers would be even better.

Injury associated with breaking through: I do not have much good data for this but it is likely that people falling in at speed from a vehicle, sailboat or skating fast sometimes are injured.  I know of an instance where a sailor dropped a runner into a pressure ridge, broke his leg and ended up in the water.  You can hit your head pretty hard in a bad skating fall.  Being in the water with a broken leg or dazed from trauma will go much better with flotation than without.

Getting out is significantly easier with flotation. If you are in the water with someone else (like a child or dog), flotation will make it more likely you can effectively help them get back on the ice.

There are a number of reasons why people don't wear flotation: They think of ice as something equivalent to solid ground,  the bulkiness of a life jacket, the cost of a float coat or float suit, fashion/machismo and, probably most of all, the belief that you will not fall in.  

Your chances of falling through are a lot higher than most people think. Swedish skaters fall through at a rate ranging from once in 200 trips for moderate skaters to once in 100 for more aggressive or less careful skaters who push the risk envelope more. I expect that rate for most activities on lake ice is in the same ballpark. If you spend much time on the ice, expect to get wet once in a while.

The  bulkiness can easily be addressed with an inflatable PFD or a float coat. See the note at the top of this page about inflatable lifejackets when walking on well thawed ice or riding in inclosed vehicles. If you spend much time on the ice, the cost of either is small compared to the protection they offer. As for the fashion/ego concerns, when you do things that involve significant risk, fashion is properly defined by function, not the other way around. 

  For snomobilers and fishermen  there are two piece suits with flotation that also offer some cold water protection (see note 4 below for www sources of these suits).  They may not be available at your local snowmobile shop). Given the number of fatalities associated with snowmobiles on ice, these suits are an excellent idea.  Click here for an excellent video featuring cold water exposure expert, Dr Gordon Giesbrecht, on just how effective these suits can be.  It will make you a believer!  Dr Giesbrecht is a strong swimmer but, in typical snowmobile suit, he was only able to swim 50 feet before becoming too debilitated to swim farther.  It took him 6+ minutes while his riding partner had a fotation suit and swam the entire 300 feet back to the ice edge in less time.  Ice claws will be handy for getting back on the ice when you get there.

Jim Hudson, a well known Wisconsin fishing guide died in the Bayfield  (Apostle Islands) area of Lake Superior in January 2013 when his sled broke through a thin area of what was mostly 10" ice.  He usually wore flotation but did not have it this day.  A friend, who was in a flotation suit, was unable to rescue him by himself.  He broke through twice in the process of trying. He attributed his surviving to his flotation suit.  The local rescue team had Jim out of the water in 30 to 45 minutes but without flotation, it was not soon enough. Click here and here for two reports.

In Scandinavia, the established practice among skaters is to carry a pack containing a set of dry clothes in a waterproof bag.  The pack may need a leg loop  to keep it from riding up when you are in the water.  A tight waist loop helps as well.  The pack should not be placed too low on your back as it will tip you forward more strongly. This method has proven to be effective in many swims, over many years of use by wild ice skaters.  Having flotation on our back is not the ideal place for it if you are going to be in the water for a while.  In Scandinavia, the near universal use of ice claws, throw ropes, training and always traveling in groups makes is very likely that you will be back on the ice quickly and into dry clothes shortly after that.  Click here for a Swedish video showing just how well this system keeps you afloat. As you can see in the video you need to actively swim to keep from tipping face down so this method is not great for situations where you can't get back on the ice promptly.  In situations where you are with a well equipped, skilled group this is unlikely to be a problem.  On the other hand, if you have not practiced getting out with this method in cold water or you are with an inexperienced group or you are alone, a life jacket is probably a better choice (you still need that bag of dry clothes however).  Click here for a report (in Swedish) on some trials with this method in a pool.  It reviews the advantages and shortcomings.  Google translate will give you the general idea of what is being described. The author  is Johan Porsby.  We are starting to use the Swedish method in Vermont.  The change of clothes has been handy in one partial immersion already. One thing I have found is that dry bags that look nice an plump when put in your pack leak air slowly as a result of the light confining pressure from the pack.  You should put enough stuff in there to keep it's volume high enough or put a tied plastic bag inside the dry bag for the same purpose.

A few of us are starting to wear breathable dry suits which provide substantial short term flotation in addition to good cold water protection (assuming you have enough clothes inside the suit).  If you are the only one in a group with a dry suit, you may be called upon to go into the water to get someone who can't get out on their own.  In this situation wearing a life-jacket is a good idea. The FIRST thing to do is call 911.  You also should know what you are doing as you are unlikely to be able to rescue someone in the water without a throw rope.

  Wet suits provide considerably less flotation but have significant, short term cold water protection.  A life jacket is a prudent addition.

 A couple differences of opinion: There are two schools of thought on auto-inflating life jackets. They are designed to inflate as soon as they get wet or see rising hydrostatic pressure (depending on the trigger design).  My West Marine 'water contact' auto inflation jacket will inflate within two seconds. On one hand the life-jacket is most likely to inflate and get you to the surface even if you hit your head in a fall.  On the other hand, if you plunge in through the ice in a way that puts you under the ice sheet, it might be problematic to have it inflate and pull you to the bottom of the sheet before you find  the hole (if you do find yourself under the ice, in addition to avoiding gasping in water,  you should look up to see where the hole is and what is floating in in the hole). 

The considerable experience in Sweden with skaters suggests that the 'under the ice, can't find the hole' scenario is very unlikely, whereas hitting your head on the ice as you fall through is a definite possibility.  Richard Saltonstall, a former Navy Diver, feels the 'stuck under the ice' scenario is plausible enough to be of concern.  One thing you can do if you find yourself on really dodgy ice is manually inflate the life jacket.  Once inflated it is less likely that you will go under if you do fall through.  The extra peace of mind is well worth the $25 it will cost to re-arm the jacket (or no cost if you blow it up yourself).

There are also two opinions on wearing flotation inside enclosed vehicles. One view is that having one on will make it harder to get out of the vehicle and may, if you leave the vehicle after it is submerged, get floated up under the ice sheet away from the hole. Dr Giesbrecht's work clearly says you should be exiting the car through the windows as soon as the car breaks through and while it is still floating - SEATBELTS-CHILDREN-WINDOWS-OUT - (2). He points out that the likelihood of surviving a car/truck breakthrough is poor once the vehicle sinks. 

They found in trials with larger trucks that even when the cab was full of water that flotation was preferred by the test subjects (who were very competent swimmers and had SCUBA equipped back up). Further study was proposed (3).   A situation where having a life jacket on might be a problem is with a big person who is already a tight fit in the window.   Also, if you have an auto-inflating PFD you should verify that you will fit through the window if it inflates before you are out.  At a minimum life jackets should be carried in the vehicle and kept on the seat so you can take them out the window with you.  It is not easy to put a life jacket on in cold water but good swimmers seem to be able to get it done. A float coat or float suit might be the best bet for enclosed vehicles as they are less bulky for getting out the window.

Bob

 

 

Reference 1) Hypothermia Frostbite and other Cold Injuries, Second Edition, G. Giesbrecht and J. Wilkerson, The Mountaineers Books, Page 59-67.  Note:  This book is an excellent source of source of information and perspective.

Reference 2) Hypothermia Frostbite and other Cold Injuries, Second Edition, G. Giesbrecht and J. Wilkerson, The Mountaineers Books, Page 130-133

Reference 3) Exit Strategies and Safety Considerations for Heavy Machinery Occupants Following Ice Failure and Submersion G.Giesbrecht and G. McDonald, 2010, Pages 8,11 and 13

Note 4) Sources of flotation suits for snowmobiling, fishing, and/or hunting:

Mustang Survival: suits for many applications

Striker ice fishing suits

Arctic Armor ice fishing and hunting suits