If you have ever been interested in ice fishing, you have probably heard about ice fishing with a flasher. By using sonar, a flasher displays objects detected in the water column on a circular screen. The display allows the angler monitor depth and view fish activity in relation to their lure. Let’s take a more in depth look at ice flashers, how they work, and how they can help you catch more fish.

Features of an Ice Fishing Flasher

Let’s walk through setting up your flasher on the ice and dialing it in. First, hang your transducer roughly 1 ft beneath the ice in your hole. Next, turn the unit on by twisting the range to its first depth. This depth is typically 20 ft. If you only see a small bar of red at the top of your flasher you are in greater than 20 ft. Turn to the next level until you see a few inches of red on the left hand side of the screen. Next, adjust he gain dial. This dial adjusts the sensitivity of your sonar to better identify your lure as well as fish relative to the bottom. Dial it down if you are targeting large fish on a larger lure or turn it up if you are targeting small fish on a smaller lure. Next up, interference reducer (IR) is a button that helps keep your display clear when fishing in close proximity to a second sonar unit. IR will reduce the distortion but giving yourself a few feet of space from a 2nd flasher is typically necessary. Lastly, some models sport a zoom feature which will allow you to monitor the entire range of the water column on the right side of the dial as well as a 5 ft zoom of the bottom on the left side of your display. Basic models such as the Marcum M1 or Vexilar FL-8 flasher sport these general features and are great for beginners.

How to Read a Flasher

Getting your flasher set up is a start, but learning how to read a flasher will expand your ice game. The flasher displays the bottom of the lake, any cover present, your lure, and of course fish. Color indicates the size of the object on your sonar: Red = Large, Yellow = Medium, Green = Small. When you drop your transducer in the hole, the flasher will display the bottom as a large bar of red. If there are green bars on the bottom, they typically mark weeds and vegetation. If there are green/yellow lines on the bottom, this may be the mark of a fish holding tight. Red/yellow lines just above the bottom typically indicate fish. As you drop your lure down, the flasher will display it moving through the water column as a yellow/green bar. You can tell the difference between the red bottom and a red/yellow fish if the colors move and separate from the bottom.

Bottom Circumference and Cones

After you get used to the basic functions of ice fishing with a flasher, understanding bottom circumference and flasher cones will help you find fish faster. The sonar from a flasher is a cone that starts at the transducer and expands down to the bottom. As the depth of the water increases, the overall circumference of the cone will get bigger. For example, if you are fishing in 20 ft of water your cone will be 5 ft wide. If you are fishing in 40 ft of water your cone will be 10 ft wide. Fish on the very outside of the cone will give weaker returns to the flasher (greens & yellows). Likewise, if a fish is directly below the transducer, the return will be strong and will offer thicker red line on the screen. As you drop a bait down, the fish on the outside of the cone will react by moving towards the bait. Since your lure is directly beneath the cone, the yellow/red bars of a fish will get larger as it draws closer.

Jigging and Reading Fish on a Flasher

Now that you have the features and color system down, it’s time to start jigging and reading fish on a flasher. When a fish shows up, it may flicker some or change colors of thickness. That is a good indicator that a fish is moving around, in and out of the cone. When a nice thick line is detected, quickly drop your bait. As it falls, keep an eye on the flasher to gauge where the bait is in relation to the fish. Usually, panfish will react as your ice jig falls, especially as you begin to give it some action. A good starting spot is to work the bait slightly off the bottom to see if anything is interested. As the fish gets closer to the bait the line will appear thicker. It will look like the bait and the fish will merge together. This indicates a likely bite. Work the bait upwards above the fish providing some subtle shaking action. Fish may follow the bait up the water column before making a charge to bite. Draw them up until they quickly close the gap to the bait and bite. While flashers can show you an impending bite, it is important to set your hook according to the indications from your rod tip.

Mobility Tactics with a Flasher

One of the major benefits of this technology is the ability to cover water. The mobility tactics with a flasher are key to finding schooling fish that are on the move. When your ice fishing for crappie or panfish, you need to keep moving as they roam throughout the day. Ice fishing with a flasher lets you check holes for fish as well as fish them fast. Check the hole to see if there are any red/yellow lines separated from the red bottom. Most of the time, you actually need to fish the hole for a bit to see if there are any fish within 5-10 ft. If you don’t see any fish on the flasher within 3-5 minutes you know its time to fish the next hole. You can fish fast with a multispecies ice rod that allows you to switch out lures for different species as you hop from hole to hole.

Identifying Bottom Hardness

Other important things that can be identified with a flasher are bottom hardness, weeds and other cover. An all red or thinner band of green lines at the bottom of the flasher indicates a hard bottom. Sonar cannot penetrate into a harder bottom so it appears as a dark solid return. Sonar will penetrate further into a soft bottom and it will show a wider band of less solid returns. Another way to identify if you are fishing soft bottom is to watch the bait as it falls. It will appear to have reached the bottom but will still fall some more. In these conditions, drop the bait to the bottom and then work it higher in the column slightly above the bottom. When ice fishing for perch, they often lay in the silt and need to be pulled upwards. Look for fish as they separate towards your jig.