Garmin 340c NOTE:, Hard Structure, Soft Structure

Getting Started > Understanding the Fishfinder and Sonar

Surface

Waterclutter depth

Depth

scale

Bottom	Suspended
	targets

The strongest sonar returns appear on your screen as the most intense solid color (depending on your selected color scheme; red is the default). The weakest returns appear as the less intense, less solid colors (blue is the default).

The bottom of the water is always going to be the strongest signal, and therefore the most intense color. The bottom is the continuous, intensely-colored line running across the bottom of the screen. The Fishfinder 340C includes the latest technology in interpreting bottom signals; it can see through fish, structures, and thermoclines (shown in the weakest colors). Large schools of fish or dense structures close to the bottom can affect water depth return readings.

NOTE: If the Fishfinder is unable to track the bottom for any reason, the digits which indicate depth flash on and off to alert you that the Fishfinder is not tracking the bottom.

Along the top of the screen, you might see a grouping of intense colors. This area is surface clutter, which can be caused by waves or any other sonar interference at the surface of the water. Too much surface clutter can obscure your view of fish. You can turn down the Gain setting to reduce this surface clutter.

Between the bottom and the surface clutter, you see suspended targets in the previous illustration. Here, the targets appear as arches. Actual suspended target returns might not always appear as perfect arches, due to the speed, fish orientation, or other conditions. You can turn on the Fish Symbols setting if you want to see suspended targets indicated by a fish shape.

The strength of the sonar return can also help you interpret the hardness of the bottom of the water. The thicker the bottom line, the harder the bottom.

Hard Structure Soft Structure

Fishfinder 340C Owner’s Manual