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Electronics

In "Electronics", Richie White covers all of information a bass angler needs to know when looking for or using electronics.

Electronics

It seems like the manufacturers of electronics want to keep us all in the dark. They have so many models with so many features and no way to compare apples to apples. They may tell you how many kilohertz that they operate, but what good is that if you don't know what that means? They may give you the cone angle, but don't tell you how to measure the angle, so you have no idea how big of area is shown under that transducer. They may tell you the difference between a narrow and wide cone area, but fail to mention what degree they consider to be wide or narrow. They tell you how many watts of power the unit puts out, but they don't tell you how many watts you need. What about fish arcs? The picture on the boxes always have nice fish arcs, but most units fail to produce anything resembling what is on the box. What about resolution? How many pixels is enough? Is it worth paying double for twice the pixels? What about mapping and GPS/WAAS? Will it help to catch more fish? What about features? Go to Lowrance's website and you will see words like FlashGraf™, COLORLINE™, HyperScroll™, FasTrack™ ASP™, Advanced Fish Symbol I.D.™, and FishTrack™ just to name a few. Who has time to learn all those definitions? Who really cares who can create the most intelligent vocabulary?

If you are confused, surely you are not alone. I have read lots of manuals and articles, I have been guiding for several years, and I also have a college degree. But I still don't know all there is to know on the subject. However, I will share some of what I have learned in the following.

How they work

Without getting technical, here is my understanding of how depth finders work. A depth finder powers a transducer that is located either on the back of the boat, the trolling motor, or it shoots through the hull. The transducer transmits sonar (SOund, NAvigation, and Ranging) waves in the shape of a cone. The waves get spaced out more as they go deeper. When the waves strike an object (fish, structure, bottom, etc.), they are reflected back to a receiver in the transducer. The signal is then sent to the unit and displayed for us to see. These waves are sent at high speeds so that they are displayed several times per second. Most depth finders will display each echo as a pixel on the right side of the screen and the chart will move to the left. The right side will show what is currently in the cone. What you see on the left has already passed through the cone. Most units come in either high frequency (192-200kHz), low frequency (50kHz), or dual frequency (50/200kHz). This can be very confusing because cone angles can be considerably different at the same frequency. Narrow cones are better suited for deep water applications while wider cones are better for shallow water. If you are fishing for bass, you will probably want a high frequency unit with about a 60 degree cone. If you fish deep salt water, you may consider the low frequency or dual frequency unit. With a 60 degree cone angle, you will see approximately 1.15 times the depth. For example, at 10 ft deep the cone will spread out to reach 11.5 feet across. At 20 ft deep, it would span a diameter of 23 ft across. A narrower cone angle of 30 degrees would show approximately 1/2 times the depth. At 20 ft, it would span a diameter of 10 ft. Conversely, a wider a cone angle of 90 degrees would show 2 times the depth. That would span a diameter of 40 ft at 20 ft deep. If you turn down the sensitivity, it will narrow the cone angle.

Complexities

If you think reading a fish finder is like looking at a television monitor, you have a lot to learn. It would be great if it were that easy. But in reality, reading a graph can be a challenge even to the most advanced fishermen. As mentioned in the previous article, the sonar constantly sends signals in the shape of a cone and whatever gets picked up is displayed at the right side of the monitor. Unless you see a continuous line touching the right side of the monitor, what you see on the screen is no longer in the cone. The majority of what you see is what was under the boat - not what is under the boat. To make matters more complicated, if a fish passes through the cone, you can't tell what direction it came from or which way it went. You also have to consider boat movement. If your boat is stationary and a fish passes through the cone, you know it was the fish that moved. But even if you are stationary, when a wave moves the boat up and down, everything in the cone will also go up and down. The bottom line is that you are always trying to interpret a moving target. Now lets add some more variables to the complexity. What about cone angle, sensitivity, bottom composition, bait fish, structure, thermoclines, different varieties of fish, surface clutter, interference, lures, etc.? We haven't even mentioned features and limitations of particular graphs. What about screen resolutions, chart speeds, fish ID, greyline, ranges, zoom, etc.? These settings will all affect what you see on the screen.

Reading a Graph

I hope I didn't get you too discouraged in my previous article. As complicated as they may be, electronics can be very valuable assets. They can tell you the depth, bottom composition, cover, thermocline, as well as the size and location of fish and baitfish. I will further discuss each of these items.

Depth

Obviously, a depth finder is designed to show the depth. Most units not only have a range on the side to show the depth, but they also have a digital reading of the current depth. As the boat moves, the distance between the transducer and the lake bottom at the center of the cone is displayed on the unit. As you travel across humps and channels, you can get an accurate reading of the terrain.

Bottom Composition

You can tell whether the bottom is hard or soft by how much gray is displayed at the bottom. Usually, the more gray, the harder the bottom.

Cover

You can get an idea of what kind of cover is below by how the objects look and the depth of the water. Trees will usually be spikes from the bottom and will often have gray inside them. Grass will be a thick, uneven band at the bottom with no gray inside it. Grass doesn't usually grow in deep water, so you will probably only see it in less than 15 ft of water.

Thermocline

During the summer months, most larger lakes will have a thermocline that you can actually see on a good graph. The thermocline is the area where the water temperature makes the most drastic change. This will show as a horizontal bar on your graph. It is very advantageous to find this thermocline in the summer because this is where a large majority of fish will be during the day.

Fish arcs

The reason a graph will display fish as arcs is because of the cone shape of the sonar waves. The further away from the center of the cone, the greater the distance to the signal and the weaker the signal. When a fish enters the center of the cone, the signal is stronger and the distance is shorter. So the signal starts out deep and faint, gets shallower and stronger, and then gets deep and faint again. The result is an arc. An arc can be created by either the boat moving across a fish or a fish moving under the boat. An arc that starts low and goes up but doesn't go back down may well be a fish moving upward. Likewise, a downward arc indicates a fish going down. A unit must have a fast chart speed and high resolution in order to display an arc. If the fish ID is turned on, it will show a picture of a fish instead of an arc.

Baitfish

Baitfish usually group up close together by the hundreds or thousands. When you have this many signals constantly getting received all over the cone, the result is a blob or balls of baitfish.

Setting a Graph

Getting your graph set properly is getting easier with the evolution of better electronics. Many of the newer graphs will draw great pictures without changing a setting. However, most of us will want to tweak our units whether they need it or not. There are really only a few things that I believe are important to tweak a graph. They are the mode, sensitivity, and range. I will discuss these in further detail.

Mode

Most units have an automatic mode and a manual mode. On most of the older units, either you let automatic mode do everything for you or you did everything yourself. Many of the newer units allow automation of separate components such as sensitivity and range. I believe this is a big step forward. If your only option is manual or automatic mode, I recommend using the manual mode in most cases. The exception would be if you are learning the terrain and automatic mode is the only way to get the range to change with the terrain.

Sensitivity

Raising the sensitivity will show more targets, but will also show more noise and clutter. Lowering the sensitivity will show less clutter, but may miss some targets. I recommend that you have the sensitivity at least high enough to produce a double echo at twice the depth. For instance, if you are in 20 ft of water, set the range to at least 40 ft. If you don't see the bottom at 20 ft and again at 40 ft, increase the sensitivity until you do. Once you get it set, then set the range back to the appropriate depth.

Range

I like to have the range set to exactly what is under me. For instance, if I am in 20 ft, I like to have a 0 to 20 ft range. Unfortunately, the units I have used do not range as I would like. In manual mode, if you have the range set for deep water and then you go to shallow water, you will only be using a portion of the screen to display the entire cone. On the other hand, if you are set for shallow water and you go to deep water, you won't see the bottom without readjusting the range.

The older units only range automatically in automatic mode. The problem with that is that in automatic mode you lose all your manual settings. I have one of the newer units with an auto range feature. This is a great feature since it doesn't change my other settings. However, it still falls short in ranging exactly as I would like. I have a graph on the front of the boat that doesn't have a preset range between 10 and 20 ft. So, if I am fishing in 14 ft of water, I have to manually set the lower limits to that depth. It can be a chore, especially if I go back and forth between shallow and deep. I prefer to keep the lower limits as deep as I plan to fish. If I know I will be bouncing back from 12 to 18 ft deep, I will set the lower limits to 18 ft. I don't usually do anything with the upper limits, because I never fish deep enough to matter.

Annoyances

Annoyances are what I call features that don't serve a useful purpose. I'm not going to mention them, because there are more of them than useful features. If you ask me, the sonar companies could have made things real simple. If they had a sensitivity up and down button and a range up and down button, that would be all we really need. Wouldn't that be neat to just push a button rather than scroll through a bunch of useless features? I guess if they made them that simple, you wouldn't be reading this.

Choosing a Unit

Choosing the right fish finder can be a challenge, considering all the makes, models, and price ranges to choose from. I will give you a few things to consider, so you can make the best choice.

Whatever you buy will be obscolete tomorrow

Keep in mind that fishing electronics are just like computers. They are necessary and helpful, but not good investments. The top of the line today will be old news in a few months. Always keep this in mind when you are making your decision. If you are one of those guys who has to have the top of the line, you can expect to spend a lot and do it often.

Get what you can afford

You probably aren't going to catch more fish just because you have the top of the line equipment. A person who knows how to use the best graph on the market should also be able to do just fine with a step or 2 below it. If you can afford the best and not have to sacrifice fishing time to pay for it, then go for it.

If you are a bank beater and never intend to learn how to use your graph, a high end graph is a waste of money. I recommend getting what you can afford, learning everything you can about it, and putting what you have learned to use.

Transducers

Make sure you have the correct transducer for you boat. There are basically 3 ways to set up your transducer: on the trolling motor, through the hull (not on aluminum), and on the back of the boat. Consider the possibility that you may switch your unit from the dash to the trolling motor when you upgrade or if one goes out. Many units are compatible with the same transducers. If you buy an older graph, keep in mind that it may not be compatible with the new transducers. You may have a choice to pay more for a dual frequency transducer. You probably won't have any reason to pay extra for the low frequency unless you are in very deep salt water.

GPS/Mapping

Mapping software is available in many of the newer fish finders. It is a big innovation that also has a big price tag. The navigation and mapping capabilities can take you right to a bridge, road bed, underwater pond, hump, etc. if your lake map is available. They can also make trails where you have been and help you navigate back to the boat ramp. I recommend you do your homework and make sure you intend to get your money's worth before making such an investment. I wouldn't recommend spending a lot more money for a graph with this capability unless you intend to get the mapping/GPS software at the same time. Your unit will be obscolete soon.

Power

Power is probably not something you should be concerned with unless you are fishing very deep salt water. Chances are, if you are willing to pay for a decent picture, you will get enough power to display it. The more power you get, the louder the sound will be. I can hear my 4,000 watt transducer in the back of the boat from the front. Lowrance claims that fish can't hear the frequency. I am not totally convinced of that. I keep my unit on when I am mobile and turn it off when anchored.

HyperScroll™

Older units only show fish arcs at a standstill or extremely slow speeds, even with chart speed at max. Lowrance has a new feature called HyperScroll™ which is intended to display fish targets at high boat speeds with more soundings per second. Many of their newer units have this feature.

Auto range

Many units require manual range changing while in manual mode. Who wants to change the ranges while trying to drive the boat?Auto range, available in many of the newer units, is a useful feature for the fisherman who uses manual mode. In automatic mode, the ranges change automatically, but so does the sensitivity and any other settings you may have tweaked.

Backlighting

The units I have used have good lighting. However, some units aren't so good. Be sure to test it before buying.

Temperature gauge

Many units offer temp gauges as either standard or optional features. This is important if you don't have another temp gauge, but keep in mind that you may be paying for another gauge that you already have. Also, if you are shooting through the hull of a fiberglass boat, you can't expect the temp gauge to work correctly since it is inside the boat.

Shallow alarms

This is a feature that can be helpful if you are driving through unknown territory and need to be alerted when you get close to ground. However, it can also be very annoying if you have it on and don't need it on.

Other features

There are many other features that either are standard on every unit or basically useless. Fish ID is one of those features that I haven't found to be useful. I expect the technology to improve here, but for now they just translate any recordings into fish pictures - whether fish, bait, stumps, thermoclines, etc. When the technology gets to where they can distinguish a bass from other species of fish, I will change my opinion. Fish alarms are another feature that I have found to be not only useless, but very annoying.

Catching Fish

I use a graph most of the year to help me catch fish. Every season is different, so I will discuss each season separately.

Winter

In the winter, the fish bunch up good in the cold water lakes. They are fairly easy to find, but hard to catch. It is tough to make a lure look alive when everything in the lake is dormant. This is not a time I like to use a graph to find fish. I prefer to use my graph to find grass in the shallows and fish for aggressive fish that move shallow to feed. I usually catch bigger fish shallow than deep. I will more often use my graph to find and catch deep water fish in the power plant lakes than in the cold water lakes in the winter.

Spring

Spring is not a time I use my electronics much. Most of the fish are shallow and I am there with them. I prefer to look for huge bedding fish and my graph is no help. I am bad about tearing up my transducers in the spring. I usually take them off during the spawn.

Summer

Summer is a good time for using a graph. I use it to find fish, humps, grass, and the thermocline. During the day, most of the fish will be inactively suspended in the thermocline. That is the best place to fish if you must fish during the day. The problem is that since the fish are inactive most of the time, it is hard to be consistent. I hate to waste my clients' time idling around looking for fish that are active. The only guarantee is that you won't catch anything until you quit looking and start fishing. I prefer to use my graph to find the grass edges and come around at dark and take advantage of feeding bass lurking around the grass. Night fishing is awesome in the summer.

Fall

Fall is absolutely the best time to use a graph. The thermocline is gone, so most of the fish are relating to the bottom. The water is still warm, so the fish are active. The lake isn't heavily pressured. And, best of all, the bass are easy to locate and get to bite. If you want to learn how to use a graph to find and catch deep water fish, do it in the fall.

Richie White