Georgia Boating Safety Course

INITIAL IMMERSION: COLD WATER "SHOCK"

If a person falls into cold water - his ir her body's initial reaction is a 'gasp reflex' which can include hyperventilationWhen breathing becomes much faster and/or deeper than normal, resulting in the loss of carbon dioxide from the blood, leading to various negative effects such as a decrease in blood pressure, fainting, etc. and muscle spasms. This initial reaction can result in water inhalation as well as significant changes in heart rate and blood pressure. These initial effects are present for the first two or three minutes of immersion.

SHORT-TERM IMMERSION: IMPAIRED FUNCTION

In cold water, a person may begin to experience the loss of basic motor skills after only a few minutes. Between 10 and 30 minutes after immersion, a person's hands quickly lose strength and sensation and subsequently the ability to swim (even strong swimmers). In cold water immersion cases, boaters often drown as a result of swimming failure before hypothermia ever has the chance to set in.

LONGER TERM IMMERSION: IMMERSION HYPOTHERMIA

Following 30 or more minutes of immersion, hypothermia - (a drop in body temperature below the normal level) will begin to set in. The overall body temperature will continue to drop until it reaches the same temperature of the water. Hypothermia symptoms range from mild to severe. As the body's core temperature falls, a person will eventually lapse into unconsciousness.