Reset Water Distance; Set Keel Offset - Eagle FISHMARK 640C Installation And Operation Instructions Manual

Main Menu (left) with Reset Options command selected. The Reset Op-
tions dialog box (right) with "Yes" selected.

Reset Water Distance

The sonar chart's Digital Data display option includes a box that shows
distance traveled, called Water Distance. This information is calculated
from an optional water speed sensor. The Water Distance window can
be reset to zero using the Reset Water Distance command.
Press | |↓ to | . The menus are
MENU MENU R W D ENT
ESET ATER ISTANCE
cleared and the water distance is reset to 0.00.

Set Keel Offset

This unit measures water depth from the face of the transducer. Since
the transducer is installed below the water surface, the distance dis-
played by the digital depth, chart depth scale, chart cursor or fish sym-
bols is not the exact water depth. If the transducer is 1 foot below the
surface and the screen shows the water depth as 30 feet then the actual
depth is 31 feet.
On sailboats or other large vessels with deep drafts, the distance be-
tween the transducer installation and the keel or lower engine unit can
be several feet. In those cases, an inexact depth reading could result in
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