Adjusting the bottom identification level (BOTTOM DECISION LEVEL)
The fishfinder picks the identification signals for identifying the bottom
and displaying "DEPTH", "BOTTOM LOCK mode", and "BOTTOM
DISCRIMINATION mode" data.
The bottom is identified automatically. However, if the bottom is heavily
laden with mud, sludge, and/or underwater plankton, the resulting noise
may cause a flickering display of the "DEPTH" value. Adjust the bottom
identification level in such a case.
Using the WHITE LINE function, specify the WHITE LINE level
separately as directed on page 44.
Outline of the procedure: Proceed from the FISH FINDER
SETTING menu to "WHITE LINE", "HI/LO", and data entry, in that
The bottom identification level adjustment procedure is shown below.
Display the FISH FINDER SETTING menu by pressing the
Move control to "INITIAL SETTING" by pressing the
key, and display the INITIAL SETTING submenu by pressing the
Move control to "BTM. DEC. LEVEL" by pressing the
key, and display the BOTTOM DECISION LEVEL submenu by
Select either "HI" (high frequency) or "LO" (low frequency) by
Specify the appropriate identification level by pressing the
1The standard value is "0".
2If the bottom is dirty with mud and sludge (under the
conditions that the edge of the bottom is not clear) and this
causes a flickering display of the water depth value, slightly
increase the identification level (change the level in its plus
direction on the screen).
3If either the double reflection of the bottom or the fish or
plankton is mis-identified as the bottom, slightly reduce the
identification level (change the level in its minus direction).
key to return to the INITIAL SETTING submenu.
key to return to the fishfinding display.
FISH FINDER SETTING
BOTTOM DECISION LEVEL
BTM. DEC. LEVEL