Let’s say you’ve done everything right so far: you’ve told someone your voyage plan before you left dock; registered and triggered your Emergency Position-Indicating Radio Beacon (EPIRB); shot off a flare; called in a Mayday giving your location, the number of people on board and the nature of the emergency and put on your safety gear, providing both flotation and insulation.
Now your vessel is going down, help hasn’t arrived and you and your crew must abandon ship. Your safety plans and the decisions you make while in the water could very well save your life and the lives of your crew.
First things first — slowly lower yourself into the water. Jumping in will increase the probability of cold water shock. Once you are in, your ability to breathe and keep your head above water becomes your number one priority. As soon as you enter cold water your body starts going through several physiological phases.
The first phase is cold shock — you will automatically gasp when you enter cold water and your breathing will speed up.
Try to stay calm, focus on taking even, steady breaths and avoid hyperventilation or panic. This is when you will be thankful that you wore thermal protection and your flotation gear.
This phase will last about one minute. If alone in the water assume the HELP position by crossing your arms tightly across your chest and drawing your knees up towards your stomach. If you’re in the water with one or more crew, huddle together, arms around each other’s mid to lower backs, chests close, and legs intertwined. These positions will help conserve your body heat and help delay the onset of hypothermia.
The second phase will involve the gradual loss of movement in your hands, feet, arms and legs.
After being in the water for about 10 minutes, your body will limit blood flow to your extremities in order to keep vital organs in your core protected. Meaningful movement in your arms and legs will gradually become impossible as will the ability to tread water and keep your head above water without flotation assistance.
Finally, you will start to experience the effects of hypothermia — which is when your core body temperature drops by 2°C or more. Although this doesn’t seem like a lot and you may think that hypothermia is an immediate response, it can take an hour or more before you lose consciousness.
These stages have been coined the “1-10-1” rule by Dr. Gordon Giesbrecht, an expert who studies human responses to exercise/work in extreme conditions such as cold water. Remember, you have one minute to get control of your breathing, 10 minutes of meaningful movement in your extremities and one hour before you may lose consciousness due to hypothermia.
Keep these stages in mind if you’re trying to decide whether or not you should start swimming. Swimming will force your body to pump blood back out into your extremities and your muscles, speeding up the rate of heat loss. Regardless of how well you can swim, if you can’t get your body out of the water in under an hour, it may be best to stay put and wait for rescue.
Always concentrate on your survival. Your will to survive plays an important role in getting you through this ordeal until help arrives. Remember to keep a positive attitude — help is on the way.