It takes some skill for anyone to survive a fall into cold water and knowing more about these techniques could help save your life. Wearing a life jacket drastically increases your chances of survival in cold water. It's extremely difficult to put one on after you fall overboard, but virtually impossible in cold water. Plus, in the second "swim failure" stage of cold-water immersion when you lose your ability to use your extremities (e.g. hands, arms, legs) you may not even be able to hold onto one.
Surviving the first "cold shock" stage of cold-water immersion, with the help of wearing a life jacket, involves getting control of your breathing. Anyone who has survived this experience of suddenly encountering cold water knows that feeling of the involuntary torso reflex and those first gasps of breath. To survive the first few minutes, you must stay calm and stop hyperventilating, but this can be challenging, even for strong swimmers. There is a technique that may help prevent hyperventilation and it involves breathing out through pursed lips. It's critical to remain calm and not panic during this first stage of cold-water immersion.
I've heard some people say they don't wear a life jacket because they can swim and they always stay close to the shore when they are boating. If you survive long enough to enter cold-water immersion's second stage, which is referred to as swim failure or cold-water incapacitation, your ability to swim is not going to help you much. Cold-water experts estimate that you will have less than 10 minutes when you can still move your hands, arms, and legs. However, any movement in cold water is going to deplete your body of heat 25-30 times faster than cold air. The Lifesaving Society research reports that 43% of people who drowned in cold water were 2 meters (6.6 feet) from safety (e.g. shore, boat, dock) and 66% were approximately 15 meters (49.2 feet) from safety.
Dr. Gordon Giesbriecht (a.k.a. Professor Popsicle) coined a phrase to help people understand the first three stages of cold-water immersion and the approximate time each stage takes. It's called the 1-10-1 rule. It refers to you having one minute to control your breathing, less than 10 minutes for self-rescue, and 1 hour before you become unconscious due to hypothermia.
Hypothermia is when your body loses heat faster than it can produce it. During this third stage of cold-water immersion, it's best to keep as much of your body out of the water as possible. For example, if there is a capsized boat, floating cooler, or anything you can climb up on it will increase your chances of survival. If that's not possible, there is a position, aided by wearing a life jacket, called H.E.L.P. or Heat Escape Lessening Posture that can reduce the rate of losing body heat. This position involves drawing your knees up towards your face, grasping your arms around your lower legs, and holding yourself into a floating ball. If you're with anyone else and everyone is wearing a life jacket, there is another position called Huddle. It involves staying upright in the water and circling your arms around the shoulders of others and holding on as close together as you can.
The specific amount of time you can survive these three stages of cold-water immersion depends on the water temperature, clothing, body type, and your behavior. This may be the one time in your life where body fat could actually help you. Wearing clothing is another key factor in surviving and cotton is not the best, but it still helps insulate your body. The best thing to wear is layers of clothes, made of wool or other water-resistant materials. Clothing can help trap air and increase your ability to float for longer periods of time. Even shoes or boots can help insulate your feet from losing heat. There's a misconception that people can drown from the weight of their wet clothes in the water, but wet clothes or shoes are only heavy out of the water. It's a simple physics concept, but unfortunately many people have to experience it themselves before they will believe this.
You could do all the right things described above and still become unconscious from hypothermia. However, hypothermia can happen with or without drowning. If you survived long enough to be rescued, then you are in danger of the fourth stage of cold-water immersion, called post-rescue collapse. These people need immediate medical attention to be properly re-warmed because they are subject to cardiac arrest. They must be handled gently. If possible gently remove their wet clothes and cover them with dry blankets until medical help arrives.
The bottom line is wearing a life jacket can help you survive cold-water immersion. Hopefully, you never have to use any of these techniques, but remembering the 1-10-1 rule may help increase your chances of survival.