Venturing out onto frozen lakes and ponds, in the dead of winter, is a unique thrill. It almost feels as if you are somehow cheating nature. There you are, slightly nervous, hovering a few inches over a liquid-filled hole in the ground, as if the laws of physics have been temporarily suspended. It is pretty marvelous, when you take a minute to think about it. Water, while quite common, is truly a black sheep in the molecular world. To be able to stand on a great solid chunk of any other substance, that is immersed in a liquid bath of itself, would require a great deal of engineering and some fancy scuba gear. With water, one just takes a few measurements, summons a little bravery, and off you go.
Ice may be a miracle of nature, but an ice adventure still warrants caution. It doesn’t matter if you are ice skating, snowshoeing, fishing, or snowmobiling; it is important to know how to gauge the safety of a frozen body of water.
When planning any ice activities, it is crucial to come prepared. A few simple items will ensure you are ready for the worst.
Be sure to wear a flotation device, especially when testing ice thickness. Have a spare change of warm clothes in a dry and secure place (which can include a floating dry bag). Bring an ice pick. In the event of an ice cave in, an ice pick will increase your reach and improve your grip on more secure ice. Never go out on ice alone.
In addition to these basic safety precautions, it is also smart to have extra blankets, hand warmers, and a candle, either in a dry bag that floats or in a nearby dry spot. In the event of an emergency, all of these extra items can be used to warm up slowly and reduce the risk of hypothermia.
A rough guideline to ice thickness
It may be cliché, but the best way to prepare for emergencies is to learn how to avoid them. Having a good understanding of ice strength, and a reliable way to measure it, won’t enable you to leave your safety gear at home, but it will hopefully prevent you from needing to use it. You can use the chart below, as a rule-of-thumb for measuring ice thickness.
2″ or less – STAY OFF
4″ – Ice fishing or other activities on foot
5″ – Snowmobile or ATV
8″-12″ – Car or small pickup
Remember that these thicknesses are merely guidelines for new, clear, solid ice. Many factors other than thickness can cause ice to be unsafe.
Tools for testing ice thickness
As much as the old “chuck a heavy rock out there” test may have served you well in the past, the only thing this method truly gauges is the safety of one area where a heavy rock with a bit of gravity on its side is safe. It is probably smarter to ask the park authorities for estimates about ice thickness before you leave home, and then check again with your own tool once you arrive (But by all means, throw a rock if you must satisfy that primitive urge.). Here are some handy tools you can use for checking ice thickness properly.
Ice chisels are one of the oldest methods for creating holes in thick ice. An ice chisel is simply a metal blade on the end of a long pole. The user chips away at one portion of ice, with the blade, until a hole is made. With a sharp blade and plenty of elbow grease, a hole can be made, in most ice, relatively quickly.
Ice augers are essentially large drills that are used to bore holes in the ice. They come in both manual and electric varieties. Manual augers are light, quiet, and low cost. Electric augers are a bit heavier and more costly but they make holes quickly and effortlessly.
Tape Measure or Yardstick
Once the hole has been created, use a tape measure or yardstick to accurately measure the thickness of the ice.
Ice is never even. Often the middle or deepest parts of a body of water will be the last to freeze. Deeper sections can be much thinner than shallower areas. There is one exception to this rule. Shallower areas may have outflows into streams. Since the water is moving, the ice will be thinner here. Give shallower outflow areas, on ponds and lakes, a wide berth. Be sure to test ice thickness, in multiple locations, before you wander too far out. White ice or “snow ice” is only about half as strong as normal (clear) ice, and it therefore requires double the thickness of clear ice to be considered safe.
The ice can be your winter wonderland. Just remember to look before you leap!