Cold Water Survival
New Zealand’s lakes, seas and rivers are often very cold. If you find yourself in the water, this can significantly increase the risk of drowning. As we head into the winter months this will become an increasingly important issue for those spending time in and around New Zealand’s waterways.
New Zealand water temperatures range from around 8.C – 16.C in winter, to about 14.C – 20.C in summer. When we discuss “cold water”, we are referring to temperatures of up 17.C. Comparatively, local council training pools are typically set to around 27.C and recreational pools around 30.C. Even in Summer, much of New Zealand’s water is considered cold. Drowning is an all year 18% percent of total fatalities occur during the winter months when the water is at its coldest.
The following guideline is based on studies from cold water researcher Dr Gordon Giesbrecht, and a study commissioned by Water Safety New Zealand from Otago University in 2012. Both sets of research present similar and complimentary conclusions, providing a strong framework for Cold Water Survival.
Cold Water Survival – Key Messages
- Ensure that you know water survival skills
- Always wear lifejackets when boating. If there is a possibility that you might end up in cold water, wear survival equipment or clothing that gives you thermal protection.
If Immersed in the cold water, follow the 1-10-1 guide:
- 1 minute to control your breathing – float, don’t panic and try not to hyperventilate
- 10 minutes to self-rescue, or plan your course of action
- 1 hour to incapacitation by hypothermia – can you make the safe distance you need by then? If not, stay where you are.
This guideline is based on studies from cold water researcher Dr Gordon Giesbrecht, and a study commissioned by Water Safety New Zealand from Otago University in 2012. Both sets of research present similar and complimentary conclusions, providing a strong framework for Cold Water Survival.
The Cold Water Survival Framework
Water survival knowledge
- Learn water survival skills (such as treading water, HELP positions etc), not just how to swim
- Habituate yourself to cold water to help reduce cold shock in the event of falling in (e.g. cold immersion in your shower for 2-3 minutes)
Water recreation preparation
- Wear lifejackets and other appropriate gear for the activity you are undertaking e.g. wet suits; rash shirt (boogie boarding).
- If there is a possibility that you might fall into cold water, wear clothes that give you thermal protection.
- If possible, enter cold water slowly and keep your head above water.
Safety in the water in a case of sudden cold water immersion
- Hold your breath for the first 5 - 7 seconds if possible.
- Float for the first minute to get your breathing under control. Don’t panic and keep calm. Try not to hyperventilate.
- Plan the best course of action for the situation - you have 10 minutes of meaningful movement and around an hour before hypothermia renders you incapacitated
- If you can’t self-rescue, prepare to wait for rescue.
- If you are not wearing a lifejacket, you will find it difficult to stay afloat after 10 minutes and other important life-saving/survival activities will become difficult
- If you are not wearing a lifejacket, stay with your boat!
- If you are wearing a lifejacket: can you make the distance you need to in 45 minutes? Be careful of overestimating your ability and underestimating the risk. It is risky to leave your boat / position unless there is no likely chance of rescue within an hour and you feel you are close to the shore and/or safety.
- If you start to swim, swim with your head out of water at an even and sustainable pace.
- When your decision is made, stick to it.
- Exit the water as soon as possible.
When out of the water
Remove all wet clothing and warm the person by wrapping them in dry clothing or blankets.