Garmin 2006 オーナーマニュアル

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SING

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ONAR

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NDERSTANDING

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ONAR

The wide beam is more helpful in shallow water, because it gives you a much 

wider view of objects in the water, including areas beyond the sides of your boat. 

At a 30-foot depth, the wide beam covers the area of approximately a 20-foot 

circle.

One of the first things to understand about sonar is that the transducer sends a 

beam down to the bottom of the water, much like the beam of a flashlight. The 

beam starts small near your vessel and expands as it gets to the bottom.
The Sonar Page does not show a 3-D representation of the underwater 

environment. Instead, the display is in two dimensions, much like if you took a 

picture of an aquarium. Only the depth of the item in the water is shown.
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 GPSMAP 3206/3210 includes the 

latest technology in interpreting bottom signals; it can see through fish, structures, 

and thermoclines (shown in the weakest colors). Therefore, large schools of fish 

or dense structures close to the bottom can affect water depth return readings.

  NOTE: If the GPSMAP 3206/3210 is unable to track the bottom for any 

reason, the digits in the depth window flashes on and off to alert you that the 

unit is not tracking the bottom.

At 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, the fish appear as arches. Actual 

fish 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 on-screen fish in 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.