sonar on iceBY DAN POTTS
(Published February, 1992, Utah Fishing & Outdoors)

The fellow walked up to me obviously intrigued by my occasionally beeping box. I smiled at him and continued to chew my peanut butter sandwich, reclining in my lawn chair in the warm February sun on an ice fishing afternoon at Deer Creek Reservoir.

"Is that one of those fish finders?" he casually asked.
"Yep!" came my exchange.
"Are all those beeps fish?"
"Yep!" I responded eloquently.
Beep. Beep. Beep.

"How much did that cost?" he asked curiously. Not trying to to ignore him, I put down my sandwich and reached for my fishing rod. "When it came out, it retailed for about $900," I said.

Beep, Beep, Beep.

"But my wife bought it on sale for less than 300 bucks," I continued.

My bite indicator on the tip of the rod twitched twice and I quickly set the hook.

"Three hundred bucks is too much money for me!" he exclaimed as I pulled a three pound rainbow out of the hole and on to the ice.

"Yeh, you’re probably right," I said. He then asked the classic question, "What ya usin'?"

"It doesn’t seem to make any difference," I answered. "Have you caught anything today?" (I’m surrounded by flapping trout and

"Naw, not much luck today!" he retorted.

"Maybe you’re not fishing where the fish are," I suggested.

"Naw, they’re just not biting for me!" he said.

"Well, you want one of mine?" I offered.

"No thanks. See ya later,“ he mumbled and scuffed off in disgust, ego apparently hurt.

The same kind of scenario has undoubtedly happened again and again across the ice of Utah's winter lakes over the past several years.

Portable sonar (fish finder) units have revolutionized the ice fishing sport across North America over the last decade. Starting with small but sensitive flasher units, today's sonars are incredibly versatile, easy to use and more user friendly.

The new liquid crystal display (LCD or LCR) units are now as sensitive as the older flasher units and a whole lot more fun to use. Flasher units are so sensitive that in shallow water the angler may be able to see if a fish has stolen the bait from his ice fly or not. The problem is, if he had been reaching for the hot coco at that critical moment, he might have missed the undisputable signal of a large trout that cruised through and robbed his bait —- or was that a rinky dink perch? With the new
LCDs, the signal would have been retained on the screen for some time afterwards, allowing the angler to evaluate the situation. Many is the time I've been able to re-interest a nice fish into returning to the hook to its demise, or in pulling the hook away from the hungry mouths of a school of small perch that I didn’t want to contend with. Knowing the past can influence the future.

I do not intend to advocate any one make or model over another, rather I desire to advocate those features available which may be of value to ice fishers.

After using several different makes and models of LCDs on the ice, there is one feature that is of utmost importance to me. If you can't read the screen, what good is it? A screen contrast adjustment will allow the angler to manually compensate for any "bleaching" of the readout as the bright winter sun affects the screen. Facing the unit away from the sun (and you into the sun) or using a visor may help for those units withoutthis feature.

A "zoom" feature will allow you to look at a particular depth range up close and see it in more detail. An adjustable zoom range will give you the flexibility of looking at an entire range, say, from just below the ice to the bottom, or a blown up view of, say, a limited range near the bottom. A splitscreen option that allows you to employ a zoomed-up view on one side and a regular view on the other, allows you to have your cake and eat it too! Without the split screen you may be concentrating on smaller fish near the bottom, oblivious to the movements of larger, although more occasional, fish passing through above the visible zoom range.

Another feature that is directly related to the discussion above, is that of resolution. Resolution in LCDs, is defined as the number of pixels (individual dark squares) per square inch on the screen. Obviously, the more the better, and usually, though not always, the more expensive the unit. Resolution equal to three inches of separation between objects is considered acceptable for most ice fishing applications and separation , approaching 1/2 inch is considered excellent for today's sonars.

Separation of 1/2 inch means that if two fish are only 1/2 inch apart vertically that the sonar will show them as two distinct fish and not as one larger amalgamated one. Separation of six inches or more will not allow the angler to distinguish the bottom from bottom hugging fishes like perch and walleye, or fish on a slope, or one fish from a school of small ones, or fish from weeds, etc. My newest sonar has 3/4 inch resolution, which is good enough to see if a fish is even thinking about biting!

Another feature that is of particular interest to those of us who don't like to constantly "watch TV" is a fish alarm. Fish alarms are great because they can notify you of the presence of a fish before it attempts to take your bait —— like in the introductory story. This allows you to get to the rod before it disappearsdown the hole.

Remember, Utah law states, "the angler must be within ten feet of equipment being used at all times," but this may not be close enough in many instances. The problem with many fish alarms is that they tend to beep at anything, and this can just about drive you crazy if you’re surrounded by small or unaggressive fish. The solution is an adjustable fish alarm feature that allows you to choose the relative size of the fish that you desire to hear.

The gain control allows the angler to adjust the sensitivity of the unit to see more, or less, in the water column. Most units have an automatic gain which automatically adjusts to the given water situation, however, this doesn’t always work to the angler’s advantage. On autogain, the sonar may see zooplankton or weeds that you interpret as fish. By turning a manual gain adjustment down you may save a lot of wasted time fishing for something that you can’t catch or don’t want to.

This is also a means of screening smaller fish so that you are only concentrating on larger ones, and a means of adjustingan unadjustable fish alarm. Some units even have a surface clutter control which can help to eliminate zooplankton attracted to the light of an open ice fishing hole, or signals reflecting off the lower edges of holes cut through thick ice.

(Of particular value on newer units is the greyscale - feature which allows the angler to determine what kind of bottom he is over, and distinguish between the bottom and fish lying on the bottom, and fish from weeds. This greyscale is especially valuable in finding bottom transitions from one material to another —— a prime fishing spot for many species.

Another feature attractive to many of us who tend to return to same lake and fishing situation time after time is the ability to store all of these various settings so that don’t have to start all over every time we drop the transducer down the hole. This feature allows one to merely turn the unit on and it’s ready to go with your favorite settings.

A backlit or at least a lit display will allow the angler to use the unit at night or during low light periods.

Sure, there are other features available, but they are either of little value to ice fishing or new to this author. The features
mentioned above are the ones that mean the most to me. Some features that are intended to make sonars more user-friendly may hurt
you more than help. By—in-large, the more thinking the sonar does the more it may be misinterpreting its own signals and the less you might be learning to interpret what’s really going on down there.

One such feature, the fish identification, which typically shows up as little variously sized stylized fishes, is especially useless on the ice. This feature is typically intended for use on a moving boat.

Now, I'll discuss what we call interpretation. Just because you've spent a small fortune on a sonar with all of the above mentioned features doesl not automatically mean that you are going to catch more fish. One has to know how to use a shovel
before being able to successfully dig a hole.

The most common misinterpretation made by novice sonar users is that of understanding the horizontal versus the
vertical aspects of the screen on a LCD. A flasher has only a vertical aspect (even if it is arranged in a circle). The vertical aspect is the only thing we are reading. The horizontal aspect is only time elapsed. In other words, it is only
the far right hand side of the screen that relates to the present. The past signals are found moving with time towards the left and ultimately off the screen as a function of screen (and signal) speed, which is usually set as fast as possible. So, we
interpret the size (density) of an object below us as the depth in pixels and the time that it remained in the "vision" of the sonar as the width (length) of the signal on the screen (see Fig. 1).

Another typical misinterpretation occurs when the transducer is aimed at either a sharply sloping bottom, a rock sticking up or weeds extending up off the bottom. In all of these cases the brains (chips) of the sonar have a difficult job of making sense of the confusing signal that reflects back from such objects. With the exception of the new 3-dimensional models, most LCDs simply cannot synthesize or display a multiple signal, so the unit simply averages it. For example, if the top of a rock or weed is at 20 feet and the bottom is at 22 feet them the unit might interpret the bottom at 21 feet, or it will simply flash back and forth between 20 and 22 feet. This could be confusing if you don't suspect the situation (see Fig. 2). You might be, for instance, catching fish constantly but you cannot see them on the screen, not even as mumps on the bottom. Your unit is probably averaging them out!

If fish are only appearing briefly on the screen (usually off the bottom), this is good (see Fig. 3). This means that they are active and probably cruising around in search of food. Most species are searcherswhen they are feeding. An active approach with
larger lures might take the most and biggest fish. If, on the other hand, the signals remain on the screen for longer periods and
especially if they are glued to the bottom, then, they are probably not very'active (see Fig. 3). If you can‘t catch them by using a more subtle, precise method then move to another hole or area in search of more active fish. You may be able to return later on when they are biting!

sonar ice mountOne last tip, mount your transducer on a tee with a universal joint on the bottom (see Fig. 4). The standard approach, which connects a transducer arm to the sonar unit or its box is highly restrictive, more difficult to move, always in the way, and is more difficult to adjust. By using a remote (detached) transducer arm and a long transducer cord, one can quickly and easily move the transducer from one hole to another in a small area without moving the unit. By using a long tee arm, gravity helps to maintain the vertical position for more accurate readings, and the length (depth) helps to eliminate edge-of-the-hole interference. When a fish is hooked the transducer can be easily jerked out of the way to prevent line tangling without moving the unit.

The universal joint attached to the transducer is of special value. With the ability to turn the transducer at an angle one can scan for fish in every direction simply by turning the tee. This almost results in a 360 degree sidescan type sonar, which can significantly improve your ability to find fish or fish-harboring structure. This can also reduce the number of holes you need to auger - although it rarely does for me. It's always greener on the other side.

Note: I mount a level bubble on the transducer or its holder to m ore easily return it to vertical when I'm through searching.

For me, sonar on ice is the ultimate cocktail. Sometimes my friends wonder if I don't spend too much time playing with the fish finder and not enough time fishing. But, I always content, "Ain't no reason to waste my time if there an't fish to bit my hook!"

Don't waste your money on the wrong finder features, learn to use the one you've got and fish finders will definitely put more fish of any species on the table for you.