Garmin zumo 450 - Manual (Page 10)

4 GPSMAP 400/500 Series Owner’s Manual
Getting Started
Minimum Safe depth—select the minimum safe depth for your
boat. Refer to your boat specifications for more information.
Shallow water alarm—only available if you are receiving NMEA
sonar depth data. Select yes or No .
Minimum Overhead Clearance—select the minimum overhead
clearance for your boat. Refer to your boat specifications for more
information.
aiS alarm Range—select the distance in which an alarm will
sound if an AIS vessel nears your boat ( page 44 ).
aiS alarm Time To—select the time within which an alarm will
sound if an AIS vessel is on track to intersect the Safe Zone around
your boat ( page 44 ).
If a water speed wheel is detected, a message will ask if you want to
calibrate it now. Select yes or No .
Adjusting the Backlight
1. Press and release the Power key.
2. Select Backlight .
To allow the unit to automatically adjust the backlight based on
ambient light, select auto backlight (automatic backlight is
available only on the GPSMAP 525, 526, 555, and 556).
To switch between Day and Night mode:
1. Press and release the Power key.
2. Select Color Mode .
3. Press left or right on the Rocker to switch between modes.