October 2010

Cold water survival

How to beat cold water immersion

Almost everyone knows how deadly hypothermia can be, but it’s only one of the four stages of cold water immersion that can put your survival at risk. Let’s look at each stage and learn the most important factor in cold water survival.

1. Cold shock

After falling into cold water, an involuntary gasp reflex causes the victim to take a deep breath. If the victim’s face is in the water during cold shock, the chances of survival diminish. Within minutes, the victim would progress to the second stage.

2. Cold incapacitation or short-term swim failure

In this stage, a victim’s manual dexterity, grip strength and movement speed drop by 60 to 80 percent. The arms and legs begin to feel like clubs.

3. Hypothermia

Hypothermia usually sets in after 30 to 60 minutes of immersion. When the body’s core temperature drops below 86 degrees, the victim loses consciousness.

4. Post-rescue collapse

When rescuers arrive, the victim may experience mental relaxation and decreased stress hormone output, which could cause a drop in blood pressure and lead to fainting and drowning.

Preventing drowning by cold shock and swim failure is the main challenge after immersion in water colder than 60 degrees. These two stages affect everyone, including strong swimmers and the physically fit.

Victims who wear personal flotation devices remain upright, and their heads are positioned to prevent them from inhaling water during cold shock. If they experience swim failure, their life jackets will keep them upright until they can be rescued.

Life jackets’ ability to prevent drowning by shock and swim failure make them key to surviving a cold water immersion. So don’t forget to put yours on before you shove off. –Gary Walkington

Eye splice (laid rope)

The strongest and most attractive way to install a loop at the end of a line, an eye splice forms a permanent loop in the end of laid rope for use with a cleat or bitt.

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