Walking, snowshoeing, snowmobiling, ice fishing (with or without a car), cross-country skiing,skating,and playing sports are dangerous pastimes when you don't know how to tell if ice is thick enough to withstand weight. There are ways to assist in gauging the potential safety of ice, such as observing its color, testing its thickness and being aware of external factors such as temperature, local conditions and local knowledge. However, no sport undertaken on ice over water bodies is ever without risk. If in doubt, do not go onto the ice; moreover, it never pays to be too early or too late in the season.

Skaters can always find a rink or a supervised lake area; snowmobilers and skiers can always stick to trails on land in place of crossing ice; walkers can keep off the ice and continue with their snowshoes along the trail. All out-goers should carry emergency supplies no matter how long they plan to be out nor where they plan to go.

If you have already made your observations and you still feel confident, you will need to back this up by checking the thickness of the ice.

Although a useful indicator, color alone should not be relied upon. For instance, ice of any color subjected to a running water force underneath will be weaker than ice not subject to that pressure. In general, you can surmise the following from ice colors:

Look at the ice to see if you can see any cracks, breaks, weak spots or abnormal surfaces and to identify the color(s) of the ice.. This is just an initial look to help you to decide if it is even worth proceeding to the next step of testing the ice.

Ask the locals. If you're from "outta town", don't make any assumptions. Stop at the grocery store, bait shop, local ski store and have a chat, or even drop into a police or fire station and ask questions about the known danger spots and safer spots in the area. People would rather help you out now than have to haul you out later.

Prefer ice that is checked by designated authorities on a regular basis. Such authorities may be staff at resorts, clubs or national parks or they may be government officials. At a minimum, such checking should occur daily. Ask them about their procedures if you need to know more to satisfy yourself. In the main, they will have access to quality measurement tools and procedures, along with full training in dealing with ice and ice accidents. This will save you the risk of testing and can reassure you. Nevertheless, continue to take all safety precautions.

Tell people where you are going. If something does go wrong while you are testing or recreating, already have in place the safety procedures that you will carry out for immediate rescue.

Recognize that ice will never be completely safe. Conditions and unseen or unknown factors can render seemingly safe ice suddenly dangerous. Take all care and precautions to avoid mishaps and to put rescue plans into immediate action should something go wrong.

I want to ice fish on a local reservoir, where the water surface moves up and down several feet. Is it safe to fish on if the ice is 6" thick but not in contact with the water?

Yes, it is natural for snow to weigh down ice causing pools of water. I have seen this as deep as 3 feet. Be cautious and stay clear of these areas, it is sometimes hard to see them with a fresh snow cover on top.

It all depends on the outside temperature and lake water temperature. A small, shallow bay can freeze five inches in a day at -25C/-10F, but the Great Lakes can take a month at these temperatures. If you don't know the attributes and conditions of the lake/river prior to winter, be very careful. There may be flowing water, natural springs, methane deposits and other factors that cause thin ice in areas.

About 4-6 inches of good clear or blue/black ice is good, but if you are with more than one person, it'd be a good idea to wait until the ice is 6+ inches and solid.

Use a 5 inch or more drill bit to drill through the ice if it's clear. If it goes through ft he bottom of the ice it may not be safe. Make sure an adult checks it first!

If you must go skating on thin ice (literally), ensure that the water depth is shallow (i.e. 2 - 3 feet (60cm - 90cm)). If it breaks through, you'll be soaked and cold but able to step up and out of it and haul yourself back to shore feeling very sheepish. Do not try this with children, however.

Dog sledding on ice is slightly safer as dogs can sense cracking ice. Still, do not take any risks and be as prepared for mishaps as any other winter sport.

Be responsible for others' wandering off. If you are the designated authority (for a school, sporting outing, etc.), or the person in charge, watch for people leaving your delimited area and make them return immediately. Ensure that there are plenty of markers laid out so that skaters etc. cannot make an inadvertent mistake and leave the tested zone. There should also be someone with first aid training on hand, along with safety equipment.

In the occasion you must cross the ice, the best way to cross is to get on your hands and legs and straddle across. Think of how a lizard moves almost, shifting your body weight evenly across your entire figure. It is a good idea to bring a long board or pole. If it starts to crack--and sometimes you get a second or two warning--lay the pole flat on the ice and use it to distribute your weight.

Never intentionally cross unsafe ice with a snowmobile. It is an invitation for disaster for a person following your tracks. The water spray in the motor compartment can also sometimes stall the engine. Some states have made snowmobile open water crossing illegal.

Never drive a vehicle onto ice unless the ice has been professionally tested and passed as safe. Even then, breaking through still happens sometimes. If you must drive, you can prepare for problems by not driving too fast, leaving down windows (turn the heater up if it bothers you!) and unbuckling your seatbelt.

Never walk, skate, play on, ski over or snowmobile over ice at night. You will not be able to see anything if something does go wrong and rescue help is much less likely to be around.

If you are following a ski or snowmobile trail, do not use ice-covered streams, rivers, ponds or lakes as a shortcut unless it has been officially designated as a shortcut by local authorities who test it every day. Shortcuts are often taken at the end of day when the sportsperson is tired and just wants to get home and the light is dimming; it is also often when an accident happens precisely because you are tiring. Also, the day's warmth has worked on the ice by day's end, so ice is weakest at this time.

In an emergency, if ice breaks under your snowmobile, do not stop. A snowmobile may be able to cross a limited amount of open water if momentum is kept up. This is do to the paddle wheel effect of the track spinning and the skis displacing water at speed. Instead, make a gentle arcing turn that allows you to keep plenty of momentum getting back to land or safe ice. A higher to full throttle setting keeps the track paddle wheeling through slush or water.

This article is applicable to very cold climate countries and regions such as Canada, upper USA and Russia. If your country or region does not normally experience deep winter conditions, consider your ice to be unsafe at all times and do not attempt to perform any of these activities on it without professional advice, preferably from a local government body authorized to provide such advice.

Snowmobilers should take care not to drive too fast - if they can't see what is up ahead, they may very well drive into a hole because they can't stop in time. Moreover, vehicles have little to no traction on ice and having to make a sudden turn away from a hole may not be possible. Spinning will be more likely and you may slide into the hole. Stay on the land and snow instead.

Just because the area of ice you tested appears safe, this does not ensure that somewhere in a different part of the same water body will be safe. If you intend moving beyond the area you have tested, you should test again, or delimit the area that you will use.

Never drink during winter sports - wait until you're back in the chalet or your home. Alcohol can impair snowmobile driving, the reaction time and the ability to deal with an accident. Alcohol does not help relieve cold; it actually makes things worse and can lead to hypothermia.

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