Ice Fishing - Ice Safety

Once you’ve walked on the ice, you need to calculate and make observations on the area of ice you want to support a load. Therefore you need to ask yourself several questions:

How thick is this ice?

The thickness of ice is calculated by drilling holes with an ice auger. It’s done by drilling a hole, then checking the ice thickness every 150 feet along a chosen path. If the ice thickness is variable, this should be done a lot more often. When drilling the holes, you should also note whether the ice in the hole is black ice, or snow ice. You should measure the thickness of both types.

How thick does it have to be to be safe?

You can work out the ice safety in two different ways:

1. You can use the formula shown below - h is the ice thickness (inches) and P is the load (tons)

   

2. You can use the table shown below

Points to think about before using the table/equation.

- Both of these ways are completely valid as long as the load is spread out over a reasonably sized area of a continuous ice sheet. The bigger the weight - the greater the area it needs for the table + equation to remain valid. Note: Large weights that are positioned in relatively small areas are not safely described by the equation/table. Look for other advice for such situations.

- The above methods of calculating ice safety assume that the ice is good quality and clear. If the ice is white and bubble-filled, count it as half as much clear ice.

- Large air temperature drops make ice brittle. If this occurs, ideally, you should wait up to twenty-four hours to approach the ice, as it may not be safe.

- If you’re using the equation and the air temperature has been above freezing for 6 or more hours during the past twenty-four hours remember to multiply the weight by 1.3 before calculating.

- Cracks occur in different places on the ice. Dry cracks are not a concern. However, if there are wet cracks, multiply the weight by two.

- When planning on leaving a load on the ice for an extended period of time, multiply the weight by two.