How to Read a Humminbird Fish Finder

Press the "on" button to power up the fish finder.

Look at the digital readings that appear on the screen. Depending on the model of Humminbird fish finder you have, these could could be depth, water temperature, and boat speed readings. Keep in mind these readings are based on the location of the transducer that sends sonar signals from the water to the fish finder.

Study the bottom of the screen, in particular the line that crosses it. This is the bottom of the lake, river, or reservoir. The undulations on the screen mirror the terrain on the bottom. A thick, dark line represents a hard bottom, while a thin, light line means the bottom is soft.

Look above the line that represents the bottom. Lines or other objects that extend up from the bottom likely are submerged timber, rocks, or aquatic vegetation. Abundant lines or objects in close proximity to each other indicate the density of the timber, rocks, or vegetation.

Observe the entire screen of your Humminbird fish finder. Oftentimes, arches on the screen represent fish. On some models, fish icons represent fish. Make note of where these objects are in the water column, but keep in mind that most fish finders cannot decipher the difference between fish and other items that might be in the water. While the icons vary in size depending on the size of the object or fish in the water, keep in mind this can be skewed by a number of factors, including the position of the fish or object when the boat passes over it.