Raymarine GPM400 Reference Manual page 103

Power setting
The power setting controls the power level of the transducer.
Auto
This is the default setting. When it is selected the DSM automati-
cally determines the required power setting based on the current
depth, speed, and (bottom) signal strength.
Manual
If you wish to manually adjust the power to suit current conditions,
you can adjust the power level between 0% and 100%, in 10%
increments. Lower power levels are normally used in depth ranges
less than 8 ft. (2.4 m) and higher power levels are typically selected
for depths greater than 12 ft. (3.7 m).
To change the power setting
1. Press the ADJUST softkey for the preset you are using.
2. Press to the manual or auto setting on the POWER softkey.
3. In manual mode, use the rotary controller or trackpad to choose
the power setting you want to use.
4. Press OK.
8.9 Measuring depth and distance
The fishfinder display gives you various methods of measuring
depth and distance:
SHALLOW Freq1: 200 kHz-Auto
F1: 200 kHz
1768ft
VRM marker
indicating
distance
behind boat
Depth line
44
VRM marker
46
indicating
depth of target
Depth
reading
VRM 1 RANGE
ON OFF 0.787nm
D10411-1
• Depth reading - your current depth. The size and position of
this readout can be changed in the Fishfinder display Setup
menu (see page 107).
• Depth lines - horizontal dashed lines drawn at regular intervals
to indicate the depth from the surface. These are switched on/
off in the Fishfinder Display Setup menu (see
• Depth Target ID - depths noted against recognized targets.
The sensitivity of these IDs is directly linked to the Fish Alarm
sensitivity; the greater the fish alarm sensitivity, the greater the
number of labelled returns. These targets are switched on/off in
the Fishfinder Display Setup menu (see
• Cursor depth - the depth and the distance from your boat
marked by the cursor, is indicated in the data bar at the top of
the screen. This performs in a similar way to a VRM, but without
lines.
• VRMs - to indicate the distance behind your boat and the depth
below of selected objects.
103
Freq2: None
42.2ft
49
63
67
70
74
74 74
75
DEPTH
44.7ft
Cursor Depth Depth
(depth indicated target ID markers
in data bar)
page 107).
page 107).
Chapter 8: The Fishfinder