If there is a single thread connecting successful ice fishermen the next few weeks, it will be the use of electronics. Every sonar user I've interviewed on the ice the past 15 years has said the single-most important piece of gear they attribute their success to is sonar. Let a battery run low, they panic. Modern sonar is an angler's window to that silent world below the ice cap. It delineates the bottom distance below the ice, sensitive equipment even advising on bottom composition in terms of hardness, weed cover, weed thickness and height, all necessary news to the knowledgeable angler.
Weeds are home base to bug life, a trout's equivalent of the kitchen pantry.
Fail to know where weedbed edges and tops are, and a bait can be buried all day where fish can neither see nor locate it. Trout use and cruise tops and edges of weed clusters like highways. Sonar beams locate those viaducts, sensitive sonars also marking individual fish and establishing patterns. It doesn't take long to determine if fish are in the area, and if they are with any frequency, what depth they are cruising at. By late February, early March, trout have established definite patterns and preferences in travel depth.