Perils of Cold Water
Cold Water, Even Unfrozen, Still a Seriouis Danger
Mon, 01 Feb 16
Commander. Flotilla 2-2, Ithaca, NY
U.S. Coast Guard Auxiliary
As the water hasn’t frozen in the lakes yet and as we so far have experienced unusually warm weather, please do NOT be lured into believing that there are NO dangers lurking due to cold, but not frozen water.. We need to think safety first. Cold air and water temperatures pose a distinct danger, whether in a craft such as a sailboat, canoe, kayak, power boat, or even accidentally falling in from a dock. Tragic deaths from cold water and hypothermia occur each year in cold water boating accidents.
While both air and water temperature affect our ability to survive, please be aware that water will cool your core body temperature 25 times more quickly than air at the same temperature.
If you lose control of your craft and find yourself immersed in the middle of a lake (hopefully wearing a life jacket), you won't survive 12 hours in water at 60 to 70 degrees. In 50 to 60 degree water, your survival time is six hours. In 40 to 50 degrees, survival time is half that -- three hours. You'll survive for one to1 1/2 hours in 35 to 40 degree water. In water less than 35 degrees, you'll succumb fast.
The effects of cold water come in three phases.
Phase 1 – the Shock factor that creates the gasp factor and makes our breathing shallow and irregular. If the gasp factor causes us to inhale under water, it at minimal will cause shortness of breath, and the worse-case scenario is we inhale and fill out lungs. So in the first minute, we try to not, if possible, fully immerse our head and MOST importantly try to get our breathing under control.
Phase 2 – Incapacitation. No matter what swimming skill level, the cold water is going to impact our muscle movement and our ability to have the impulses that give the signal from the brain to have our legs and arms move. As always there are a lot of factors, such as actual water temperature, physical condition, etc., but figure you will have 10 minutes of meaningful movement. So, can you make it to shore or is your best bet to stay with your boat and try to get as much of your body as you can out of the water? Remember: 10 minutes before all the blood is drawn back to your core and you lose control of arm and leg movement.
Phase 3 -- Hypothermia, which is the reduction of the body’s vital core temperature resulting in unconsciousness. Most of your body core heat loss will be through your head, neck, sides, shoulders and groin. In water temperatures less than 40F, you have roughly 1 hour.
Phase 4 – Post Rescue Collapse due to the stress on your heart – ALWAYS call an EMS.
The most prudent defense is avoid getting immersed in cold water:
-- Evaluate if water temperature is too low to even take the risk. We do, after all, live in Northern New York and air and water temperatures can be cold well in to spring.
-- Avoid standing up or moving around in a small boat.
-- Do not overload a boat and make sure the load is evenly distributed.
-- Avoid sudden high speed turns.
-- Avoid sudden deceleration, which may cause the stern wake to overtake and swamp a small boat.
-- Note that below 50F air and water temperature you will need layers, a dry suit, with a PFD.
Next, anticipate that you can end up in the water:
-- WEAR your life jacket and not just have it in the boat – even if you are close to shore, or you think you can put it on while in the water, or you can swim. As noted above, there are other factors that will impact your ability to save yourself. The life jacket must fit properly and be of a style, like the vest style, or Type I, that will hold your head out of the water, even if you are unconscious. Brightly colored Life jackets are easier to see when you are in the water than blues or greens. Remember that NYS law requires that everyone aboard pleasure vessels less than 21 ft. in length, including rowboats, canoes and kayaks, while underway between November 1 and May 1, MUST be wearing a life jacket.
--Take a boating Safety Course – contact Walt Robinson @ firstname.lastname@example.org for a schedule and sign-up
-- Boat Sober
--Leave a float plan
- 1 minute to control breathing
- 10 minutes of meaningful movement
- 1 hour until hypothermia and unconsciousness
(Sources: U.S. Coast Guard, U.S. Coast Guard Auxiliary, Cold Water Bootcamp by Dr. Gordan Giesbrecht, Cold Water Boating Safety, Alaska Division of Parks and Outdoor Recreation.)