How to Read a Garmin Fishfinder

By Larry Anderson

Garmin fishfinders help anglers find fish.
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Fishfinders made by the Garmin company are useful for fishermen and pleasure boaters alike. Not only do they show the location of fish, they also show the bottom and the depth, which can help all boaters avoid shallow areas that could damage their boats. Garmin manufactures a range of fishfinders, including some that are meant for novice fishermen and boaters, who should learn to read them before moving on to more advanced versions.

Step 1

Turn the unit on by pressing the power button, which is the one with the red circle.

Step 2

Look at the numbers in the upper left corner of the screen. The top number is the depth of the water, in feet. Other numbers you may see, depending on the unit, include the water temperature, in Fahrenheit.

Step 3

Locate the line that runs across the bottom of the screen. This line represents the bottom of the lake. Read the line from left to right. If it slopes upward, the boat is traveling toward shallower water. If it slopes downward, the boat is heading to deeper water. Also pay attention to the thickness of the line. The thicker it is, the harder the bottom.

Step 4

Look closely at any lines or other objects that extend off the line. These could be items ranging from rocks to vegetation. Rocks will show up as small, dark-colored humps. Tall vegetation shows up as lines, as do submerged trees, though trees will be darker in color than vegetation. Small clumps along the bottom that are light in color probably indicate vegetation growing close to the bottom.

Step 5

Focus on the screen above the bottom, which represents the water between the bottom and the surface. Fish will show up as hooks on the screen. The larger the hook, the larger the fish. Pay attention to how far below the surface the fish are. If you are fishing along the bottom, but all the fish are 5 feet off the bottom, you may not catch anything.