These are the best ways to test ice thickness

Updated: March 18, 2019

Lake hockey rink at sunset Steven Flannigan/Shutterstock

As a kid, I usually sent my baby brother onto the ice to test its thickness. Miraculously, he never died. But there are less perilous (and more effective) ways to test ice thickness.

Cordless drill and wood auger bit Mark an 18″ wood-auger bit with tape at safe-ice depths of 4″, 6″, and 12″, and cut vertical holes in the ice with a cordless drill. The flutes in the bit will force ice chips out of the hole. When you hit water, the markings on the bit suggest how deep you drilled. A tape measure into the hole, hooked on the underside of the ice, confirms the depth.

Ice chisel or “spud” Homemade or bought, a rebar-sized metal rod with a sharp, flat blade like a chisel welded to one end and a handle on the other is sometimes called a spud. Stab the chisel into the ice, repeatedly, creating a hole. (A crowbar can work in a pinch.) Measure ice thickness with a tape.

Chainsaw Cut a 12-by-12-inch square into the ice. When it floats, tilt or lift it and measure. Ensure the square goes back into the hole to refreeze, and add a stick to flag the hazard.

Homemade test pole A 2″-dia. hardwood dowel, 60″ long, makes for a quick ice-testing poker stick. Pre-drill a 3/16″ pilot hole 4″ deep in one end. Squeeze some PL Premium adhesive into the hole, then tap in a 10″ nail about 5″ deep. Grind the head of the nail to a sharp point. Shorter versions make for good, hand-held ice picks you can use to pull yourself out of a hole should you fall through.

Hatchet With one hand, swing the sharp side of a hatchet or small axe hard into the ice. If no water appears, the ice is likely hard enough to walk on, or close to 4″. (This method is imprecise at best, so use with caution.)

No matter what method you use, always remember to test in more than one spot, says Lauren Phillips, a team leader and training officer with Prince George Search and Rescue. “There’s huge variability even just a few footsteps away.” The best and safest ice to walk on is always black (also called clear), newly formed ice. According to the Canadian Red Cross, white opaque ice (formed by wet snow freezing on the ice) is half as strong as black ice, and grey ice is deemed unsafe as it indicates the presence of water. “If you’re not sure,” says Phillips, “just stay off the ice altogether.”

Minimum depth requirements for activities on new, clear (black) ice:

Less than 4″
Stay off

4″
Ice fishing, walking, skating

5″
Snowmobile or ATV

8″-12″
Car, small pickup

12″-15″
Medium pickup or van

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