ICE FISHING IS AMONG THE MOST DANGEROUS outdoor sports, especially in March, when the ice pack is deteriorating and thickness alone is not an accurate gauge of safety. Always phone for conditions first (contact fish and game, fire, and sheriff's departments, or local sporting-goods stores), and follow these tips.

• Stay away from inlet and outlet streams. Under-the-ice current can reduce ice strength by 20 percent or more.
• Cattails and other vegetation, as well as rocks and logs, conduct heat, weakening the ice.
• Tow your equipment sled on a long rope. You can push it toward a victim who has fallen through.
• Beware of black, gray, or milky ice. It lacks the strength of clear blue or green ice.
• Eroded shore ice is a sign of a thinning ice pack. Beware.
• Ice sloping from a bank may trap air underneath, reducing its strength.
• Slushiness is a sign of a weakening pack; so is finding snow cover or water on top of ice. Depressions in the snow indicate a spring.
• Use your walking stick or ice chisel to test ice conditions.
• Carry cutoff broom handles tipped with sharp nails and attached with 2 feet of cord. Dig them alternately into the ice to haul yourself out.
• If you break through, face the ice you've already crossed. It will be stronger than ice in the direction of your fall. Crawl until you reach safe ice.
• A 50-foot cord wrapped around an empty Clorox bottle makes a handy flotation device. Stand on sturdy ice and toss it to the victim.
• Thin cracks may let you see whether the ice is thick or not.
• Pressure ridges are caused by fluctuating temperatures. Avoid them.
• Open water is a red flag, pointing to a marginal ice pack nearer the shore.