Many factors influence ice thickness, including water type, location, season, and other environmental factors such as:
- Water depth and size of body of water.
- Currents, tides and other moving water.
- Chemicals including salt.
- Fluctuations in water levels.
- Logs, rocks and docks absorbing heat from the sun.
- Changing air temperature.
- Shock waves from vehicles traveling on the ice
Ice Colour
- The colour of ice may be an indication of its strength.
- Clear blue ice is strongest.
- White opaque or snow ice is half as strong as blue ice. Opaque ice is formed by wet snow freezing on the ice.
- Grey ice is unsafe. The grayness indicates the presence of water.
Minimum ice thickness should be:
- 15 cm for walking or skating alone
- 20 cm for skating parties or games
- 25 cm for snowmobiles.
Remember that thickness is only one factor to consider when participating in ice activities, and the minimum thicknesses are only guidelines. The ice strength will be affected by local conditions as well as the type of water body. Before venturing out on the ice, check with local authorities for information on local ice conditions. Follow posted signs that indicate when and where the ice surface is suitable for activities. Avoid going out on the ice late at night.
When You Are Alone On Ice
If you get into trouble on ice and you’re by yourself:
- Call for help.
- Resist the immediate urge to climb back out where you fell in. The ice is weak in this area.
- Try to relax and catch your breath. Turn yourself toward shore so you are looking at where you entered onto the ice. The ice is more stable close to shore.
- Reach forward onto the broken ice without pushing down. Kick your legs to try to get your body into a horizonal position.
- Continue kicking your legs, and crawl onto the ice.
- When you are back on the ice, crawl on your stomach or roll away from the open area with your arms and legs spread out as far as possible to evenly distribute your body weight. Do not stand up! Look for shore and make sure you are crawling in the right direction.
When You Are With Others On Ice
- Rescuing another person from ice can be dangerous. The safest way to perform a rescue is from shore.
- Call for help. Consider whether you can quickly get help from trained professionals (police, fire fighters or ambulance) or bystanders.
- Check if you can reach the person using a long pole or branch from shore – if so, lie down and extend the pole to the person.
- If you go onto ice, wear a PFD and carry a long pole or branch to test the ice in front of you. Bring something to reach or throw to the person (e.g. pole, weighted rope, line or tree branch).
- When near the break, lie down to distribute your weight and slowly crawl toward the hole.
- Remaining low, extend or throw your emergency rescue device (pole, rope, line or branch) to the person.
- Have the person kick while you pull them out.
Move the person to a safe location on the shore or where the ice is thick. Make a call for assistance.
With thanks to the Canadian Red Cross
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