New Transducers 250C 사용자 설명서

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The following settings are available:

•  

Water Type—allows you to select either Fresh or Salt to 

ensure accurate readings on the unit. Sound waves travel at 

different rates through each type.

•  

Depth Number—controls the efficiency of the digital depth 

update rate. Fast Sonar Update updates quicker and is 

recommended for low-noise, deeper water (>50 ft.). Auto is 

best for shallow water or high noise areas, has a slower screen 

update, and is best used if you travel a wide variety of depths.  

If the unit is unable to track the bottom for any reason, the 

digits in the depth window flash on and off to alert you.

•  

Automatic Scroll Speed Limit—matches the scroll rate 

(page 19) to the speed of your vessel (if equipped with a 

speed sensor or receiving GPS NMEA input). Entering 

your maximum cruising speed will produce a 100% scroll 

rate when you reach that speed. One half of that speed will 

produce a 50% scroll rate, etc.

• 

Keel Offset—allows you to offset the surface reading for the 

depth of a keel in order to measure depth from the bottom of 

your keel instead of from the transducer’s location. Enter a 

positive number to offset for a keel. Enter a negative number 

to compensate for a large vessel that may draw several feet of 

water. The Keel Offset is reflected in the depth reading.

Transducer at surface 

Enter a positive (+) Keel Offset 

number to show the depth  

from the bottom of the keel.

Transducer at bottom of keel 

Enter a negative (-) Keel Offset number to 

show the depth from the surface.

• 

Transducer Type—allows you to specify what type of 

transducer you are using, if you are not in Simulator mode. 

Do not use User Defined unless instructed to do so.

• 

Calibrate Water Speed—appears only if you are using a 

speed-capable transducer/sensor. Calibration is required 

to ensure that the Water Speed displayed on your unit is 

accurate. The unit automatically uses GPS ground speed (if 

available via NMEA input) for comparison on the calibration. 

If a GPS ground speed is not available, use either your boat’s 

speedometer reading (not always accurate) or a stopwatch to 

determine your speed over a certain distance (distance / time 

= speed). It is recommended that the calibration take place in 

water having little or no current.