NSW & ACT
Ocean survival after 40 hours 'unlikely': Westpac Marine Services
- From: The Daily Telegraph
- May 10, 2013
THE couple who plunged overboard from a cruise liner off the NSW coast would survive have between two and forty hours in the water before succumbing to hypothermia.
Sea surface temperature charts show the ocean waters where they fell are about 20C.
According to a hypothermia chart by maritime survival experts Westpac Marine Services staying in 20C water would see "exhaustion or unconsciousness" would set in within two to seven hours.
The chart says "expected time of survival" in 20C water is between "two and 40 hours".
What the couple where wearing, and their body weight, affects survival times.
Consuming alcohol dramatically reduces survival times - alcohol increases the risk of hypothermia because it acts as a "vasodilator", increasing blood flow to the body's skin and extremities, making a person feel warm, but at the same time increasing heat loss from the body.
Body heat is lost far more quickly in water than in air - cold water robs the body of heat about 25 times faster than cold air does.
As a person's body temperature falls they become disorientated, their heart rate, respiratory rate, and blood pressure all decreases, their muscle coordination becomes very poor, they can exhibit irrational behaviour like taking their clothes off, and they eventually become unconscious.
They can still survive for some time after losing consciousness, if they are wearing as life jacket.