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Alan Fong
Fisherman's Warehouse
(916) 362-1200

Using The Fish Finder

        Depth finders are a very important tool when fishing. They are used for locating bottom structure and fish. Learning how to use one correctly will improve your fishing skills and catching ability to another level. I can not go Furuno LS6000 LCD Fish Finder fishing without a sonar unit, itís like going with out a rod and reel. I will discuss the different kinds of depth finders and help you find the right one for you. Depth finders will show you the depth of the water, trees, rocks, fish, bait and thermo cline ( where the most oxygen is). I use my depth finder like a set of eyes, I can tell what is going on at all times below me. What ever kind of fish you are trying to catch, a sonar unit will help you understand and catch more fish. There  are a lot of different brands and models on the market. Most units will have four to six hundred watts of power peak to peak, the stronger models will have three thousand watts peak to peak. The pixel count is very important to have a clear picture, the more expensive models have 240x240 and the less expensive ones have 160x160. Most sonar units are called LCR, which are liquid crystal units and are gas sealed to make them waterproof. The way sonar works is a electrical pulse converted into a sound wave by the transducer and transmitted into the water. When this wave strikes an object, it is reflected. Since the speed of sound through water is known, the time lapse between the transmitted signal and the received echo can be measured and the distance to the object determined.

Picking a sonar unit depends on the depth of water you will be fishing most of the time. Most units on the market will use a 20degree, 192 khz transducer cone, which will work best for most fishing . When you are fishing at depths of more than two hundred feet, a narrow 8degree cone transducer will work better. In 15 feet of water a 20degree transducer covers an area of the bottom thatís about 6 feet across. An 8 degree transducer covers only about a 2 foot circle. The narrower cone transducers are for deep water fishing, like salt water fishing. If you are using a 20degree transducer in 250 feet of water, the cone angle is so wide when it hits the bottom the echo will not make it back to the transducer therefore you wonít see any objects between you and the bottom. There are other sonar units that have multiple transducers and some with side viewing .

I will go over the most important settings on your sonar unit. First is the sensitivity control which is the most important to have set right, it should be at least 75 percent to full. The gray line, 6 to 12 percent or turn it off and start to increase until you get a gray bottom separation. The chart speed should always be on as fast as it will go, remember the slower the boat speed the faster the chart speed and the faster the boat speed the slower the chart speed. Turn the suppressor off, this is used to reduce interference from noise. If you turn it up to high you will suppress the signal and wonít see anything.

When fishing in a river with a lot of current it is better to graph going with the current. I have found going with the current, the fish donít spook as bad. Lake fishing it doesnít seem to matter. After fishing for awhile and using a sonar unit, you should be able to tell what kind of structure your fishing.


      Good Luck,     Alan Fong

         Practice catch and release!

You can contact "Alan":  

Fisherman's Warehouse
9035 Folsom Blvd.
Sacramento, Ca
(916) 362-1200



Check out some of "Alan Fong's" other articles:



 1. Alan's Tip On Fall Delta Striper Fishing

 2. California Delta Large Mouth

 3. Using Fish Finder 

 4. Spring Run Striper

 5. Springtime Delta Bass

 6. Springtime Shad

 7. Frogging For Bass

 8.Delta Summer Fishing

9.Vertical Spooning For SALMON


11.Night Fishing For Salmon