How To Use A Fish Finder

how to use a fish finder

Fishing is an extremely popular sport and gives pleasure to millions. There are many tales of what the best fishing spots are, or the best bait to use, and fishermen have been known to debate all aspects of the sport with conviction.

While sage advice has been handed down over the years from one person to another there have been quite a few advances when it comes to the equipment used and technology that is employed.

The global sports fishing market is expected to enjoy a growth rate of 4% over the next three years which is in line with it being the second most popular outdoor activity in the whole of the United States.

So, with recreational fishing being so popular and the market increasing there are of course some useful devices that can be purchased by any interested parties. One of these is the fish finder…

What is a Fish Finder?

In case you are not entirely familiar with what a fish finder is, it is an electronic device that employs SONAR technology to give an image of the water below a boat, for example. This image will show up fish, wrecks, divers, coral, and the bottom of the lake or other body of water.

The device will have an LCD screen where images of what is below will be displayed. These displays may be around 4 or 5 inches and depending on the fish finder’s functionality can show the real-time movement of fish as they pass through a transducer beam.

The first-ever fish finder was invented in Japan in 1948 by the Furuno brothers and was used to locate schools of sardine. However, the first fish finder to utilize SONAR technology arrived in 1957 courtesy of Darrell Lowrance. Since then the device has gone through many evolutions and is now available as highly portable devices with color screens and a range of features.

Is Using a Fish Finder Cheating?

Like any activity or sport, some people stand on one side of technology and use any advantage that can be given, and then others declare these types of devices as new-fangled gadgets.

Most fishermen would not see a fish finder as cheating. After all, a device that can save time traveling from spot to spot has to be good right? Life might be too short for some people whereas others are perfectly content to cast a fishing rod and then relax.

When choosing the equipment for fishing you would look to get the best you can and take the right tools for the job. You might ask if you can use freshwater reels in saltwater, or you might want to know the best bait to catch bass. A fish finder is just another tool available to the recreational fisherman and is no less cheating than using a boat.

How Do You Use a Fish Finder?

The first thing you need to do after purchasing a fish finder is to read the manual. This might sound dull but getting acquainted with your device early on will help you once you are on the water later.

You should be able to get the basics pretty quickly and you will gain more from experience when you are out using the device but you need to understand what the display is showing you.

It doesn’t matter which brand you have purchased as they will all show some similar information such as how deep the fish finder is measuring, the temperature, and the speed the boat is currently going.

You Need To Understand How To Read The Screen

Your device may be employed in down imaging mode or side imaging mode. When side imaging mode is used the boat will be the topmost object on the screen and everything below will be what you have passed over. The data is read from top to bottom with the top-most objects being the newest information and the oldest being at the bottom of the display.

When you use down-imaging or SONAR mode then the information reads from right to left. The right-most imaging is the most recent data with the left-most the oldest. When in this mode you can see large fish displayed as arch shapes. This may indicate larger fish such as salmon whereas blobs and dots will indicate smaller fish.

You can use the display to recognize what the terrain is beneath you. This is useful for mapping out areas that fish may prefer such as rocky areas.

If you are struggling to understand the data being fed to you then you can use a handy feature to display fish symbols directly on the display. For most seasoned users this isn’t necessary and might be too cluttered but in the beginning, you may find it useful.

Other Reasons You Might Want To Use a Fish Finder

The name fish finder implies that the only purpose for it is purely for fishing but this isn’t so. A fish finder can be a handy tool for diving also.

There are other devices called depth finders that use similar technology but these are primarily used for detecting depth in shallow waters. A fish finder, however, can map several minutes of history and a wealth of information about what is below a boat. This can be very helpful to divers when out in limited visibility as they can locate other members of their party below the surface easily.

Kayak diving is becoming more popular these days and a fish finder could be used to locate coral reefs or a wreck below a kayak. Before heading out in this style you should check if you need a boating license for a kayak in your region.

Ways You Can Use a Fish Finder

The most popular way to use a fish finder is from a boat. This may be a built-in device or a portable one, but, there are other ways to take a fish finder out with you when you go fishing.

Jet skis are being employed more in the world of fishing and once you have set up a good rig and bought all the accessories you need you might want to add one more. You can see a range of depth finders for jet skis here and these devices can help you to locate good fishing spots as well as understand the terrain below your PWC.

There are also castable fish finders that you can use from shore. These small devices are cast-off away from the fisherman and will send data back directly to the user’s smartphone. Because of the nature of these devices, they are perfect for use on river banks, docks, piers, and the shore.


A fish finder is a highly accurate and useful tool that can aid in locating good spots to fish in. Once you understand how to use the device the screen will provide a wealth of data that should improve all fishing trips and reduce wasted time.

The beauty of these devices is that not only are they small and portable but they can be used for other purposes instead of just fishing so they can be a good investment for a diver or anyone interested in mapping out bodies of water and the terrain below.


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