Outdoor enthusiasts should be sure of ice thickness, testing it with an auger or spud bar before going out. Satre said ice conditions can vary greatly and anglers should know about different types and characteristics of ice. Slush ice is half as strong as clear, blue ice. Slush shows weakening of the ice and should be considered a danger sign. Clear, blue river ice is 15 percent weaker than pond or lake ice.
New ice is usually stronger than old ice because the bond between the ice crystals decays with age.
Dark or honeycombed ice indicates deterioration and should be avoided. Even if a cold snap halts the deterioration process, dark or honeycombed ice will never refreeze to its original strength. According to ice strength figures compiled by the Lumbermen's Safety Association and other sources, 2-3 inches of clear, blue ice will support one person walking. Ice angling slow Anglers in the Iowa Great Lakes region report limited success in catching fish this ice fishing season. Most fish caught are medium size, with an occasional jumbo.