How to Read a Fish Finder

Information Guide: How to Read a Fish Finder

I love fish finders, and if you read my short tale as to how life was before finders, you’ll realize that I’d simply be lost today without mine. However, like I mentioned here as well, there are many obstacles that come with the added convenience and additional tech of these units, not to mention a decent sized learning curve. Simply put, if you’ve never had a chance to use one of these before, and you expect to just jump out on the water and catch hordes of fish, your in for a bit of a shock.

Over the years, companies such as Lowrance and Humminbird have gone through great lengths to make the interface of these devices easier to handle and navigate, but there will always have to be a balance between features and ease of use. The fish finders which do the best job, also are the most complicated to use. So to make your life easier, here is a detailed article as to how to read your display and what the different varieties of models include in each of their interfaces. Keep in mind that literally every single model on the market has a different interface which requires you to read the manual, and this is just a general guide.

Side Imaging/Down Imaging Finders with High Frequency

There is quite a bit of information that you can acquire with the best units on the market, they don’t just point you in the direction of the fishies, and some of this information is vital to us anglers. This includes information of little importance, such as temperature, to how deep the water is. Some of these new models will even do the interpretation for you and show you a symbol of a fish on the screen so there is no guesswork involved.

These high frequency models, produce excellent imaging of what lies directly beneath, and to the side of the boat or kayak, although be sure to keep in mind the variation between some transducers which can accurately track deeper waters, versus transducers which don’t. In addition, when looking at a fish finder, you’ll need to understand side imaging versus down imaging. Down imaging gives you an overlay of what lies directly beneath the vessel, where as side imaging will display SONAR images of the water directly to the side which the transducer points Most of the best units today show 360 degree side imaging.

Take a look at this image here to the right, this is what a typical advanced unit will look like with 360 degree imaging. Yeah, these aren’t really 360 degree imaging, but I’ve seen them touted as such. Notice that it shows four different screens, along with the corresponding depth and SONAR imaging. In the top left corner gives the most pertinent information, your vessel is 28 feet above the water floor, and there is an additional 10 foot increment just to show you where the fish or debris are located on the far right. On the left side of the screen is the left side of the boat, on the right side is the right side of the boat. Also notice the “120” on the picture, this indicates how wide the side imaging of the transducer picks up, and the bottom image gives you a display.

Traditional Units

The second type of unit that you can purchase, are displays which give you simple down imaging readings, or side image readings. These units are usually much cheaper, as some people find having both displays unnecessary, as they do a specific kind of fishing. For instance, if you plan on jigging, you’ll want a side imaging fish finder. If you plan on dropping your line directly underneath, you won’t care so much for directly underneath your vessel. To the left is what a screen from one of these units will look like.

This is a very nifty display, it does the hard of interpreting the SONAR and displaying the information on the screen. You’ll notice it also shows you the size of the fish. In the center top, is the location of the kayak or boat, to help the angler decide in which direction he should cast.