Eagle Electronics 640c manual Press MENUMENU↓ to SET Keel Offsetent

Models: 640c

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grounding or striking underwater structure. The Keel Offset feature eliminates the need for the navigator to mentally calculate how much water is under the keel.

Keel Offset lets you calibrate the digital depth, chart depth scale, chart cursor depth and fish symbol depth displayed on the screen. To calibrate the depth indicators, first measure the distance from the face of the transducer to the lowest part of the boat. In this example, we will use 3.5 feet. This will entered as a negative 3.5 feet, which makes the depth indi- cators perform as if the transducer's lower in the water than it really is.

1.Press MENUMENUto SET KEEL OFFSETENT.

2.The Keel Offset dialog box appears. Press to change the plus (+) sign to a minus (–) sign.

3.Press to the first number, then press to change the number to 3

4.Press to the second number, then press to change the number to 5, then press EXIT. The depth indicators now accurately show the depth of water beneath the keel.

NOTE:

If knowing the exact depth of water beneath the keel is less important, you can calibrate the depth indicators so that they show the actual wa- ter depth from surface to bottom. To do this, first measure the distance from the face of the transducer up to the surface (the water line on the boat). In this example, we will use 1.5 feet. This will be entered as a positive 1.5 feet, which makes the depth indicators perform as if the transducer's higher in the water than it really is.

1.Press MENUMENUto SET KEEL OFFSETENT.

2.The Keel Offset dialog box appears with a plus (+) sign at the front of the box.

3.Press to the first number, then press to change the number to 1.

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Eagle Electronics 640c manual Press MENUMENU↓ to SET Keel Offsetent