Radar; Radar Display Modes; Transmitting Radar Signals; Adjusting The Radar Range - Garmin GPSMAP 800 Series Owner's Manual

Decreasing the time-elapsed scale allows you to view
more detail over a shorter period of time.
• To set the depth-range or temperature-range scale, select
Scale. Increasing the scale allows you to view more
variation in readings. Decreasing the scale allows you to
view more detail in the variation.
The marine radar transmits microwave energy that has the
potential to be harmful to humans and animals. Before
beginning radar transmission, verify that the area around the
radar is clear. The radar transmits a beam approximately 12°
above and below a line extending horizontally from the center of
the radar.
When the radar is transmitting, do not look directly at the
antenna at close range; eyes are the most sensitive part of the
body to electromagnetic energy.
NOTE: Not all models support radar.
When you connect your compatible chartplotter to an optional
Garmin marine radar, such as a GMR
HD, you can view more information about your surroundings.
The GMR transmits a narrow beam of microwave energy as it
rotates to a 360° pattern. When the transmitted energy contacts
a target, some of that energy is reflected back to the radar.

Radar Display Modes

NOTE: Not all modes are available with all radar devices and all
chartplotters.
Select Radar.
Cruising Mode: Shows a full-screen image of the gathered
radar information.
Harbor Mode: Intended for use in inland waters, this mode
works best with short-range signals (2 nm or less).
Offshore Mode: Intended for use in open waters, this mode
works best with long-range signals.
Sentry Mode: Allows you to put the radar into timed-transmit
mode, in which you can configure a radar transmit and
standby cycle to conserve power. You can also enable a
guard zone in this mode, which identifies a safe zone around
your boat. If you switch from Sentry mode to another mode,
the radar switches to full-time transmission and disables all
guard zones.
Radar Overlay Mode: Shows a full-screen image of the
gathered radar information on top of the Navigation chart.
The Radar overlay displays data based on the most recently
used radar mode.

Transmitting Radar Signals

NOTE: As a safety feature, the radar enters standby mode after
it warms up. This gives you an opportunity to verify the area
around the radar is clear before beginning radar transmission.
1
With the chartplotter off, connect your radar as described in
the radar installation instructions.
2
Turn on the chartplotter.
The radar warms up and a countdown alerts you when the
radar is ready.
3
Select Radar.
4
Select a radar mode.
A countdown message appears while the radar is starting up.
5
Select MENU > Transmit Radar.
20

Radar

WARNING
™ 1226 xHD2 or a GMR 24

Adjusting the Radar Range

The range of the radar signal indicates the length of the pulsed
signal transmitted and received by the radar. As the range
increases, the radar transmits longer pulses in order to reach
distant targets. Closer targets, especially rain and waves, also
reflect the longer pulses, which can add noise to the Radar
screen. Viewing information about longer-range targets can also
decrease the amount of space available on the Radar screen for
viewing information about shorter-range targets.
• Select to decrease the range.
• Select to increase the range.

Tips for Selecting a Radar Range

• Determine what information you need to see on the Radar
screen.
For example, do you need information about nearby weather
conditions or targets and traffic, or are you more concerned
about distant weather conditions?
• Assess the environmental conditions where the radar is being
used.
Especially in inclement weather, longer-range radar signals
can increase the clutter on the Radar screen and make it
more difficult to view information about shorter-range targets.
In rain, shorter-range radar signals can enable you to view
information about nearby objects more effectively, if the rain
clutter setting is configured optimally.
• Select the shortest effective range, given your reason for
using radar and the present environmental conditions.
Adjusting the Zoom Scale on the Radar
Screen
The radar zoom scale, also called the radar signal range,
represents the distance from your position (the center) to the
outermost ring.
From a Radar screen, select
Each ring represents an even division of the zoom scale.
For example, if the zoom scale is set at 3 miles, each ring
represents 1 mile from the center out.

Marking a Waypoint on the Radar Screen

1
From a Radar screen or the Radar overlay, select a location.
2
Select New Waypoint.

Sentry Mode

Sentry mode allows you to put the radar into timed-transmit
mode, in which you can configure a radar transmit and standby
cycle to conserve power. You can also enable a guard zone in
this mode, which identifies a safe zone around your boat and
sounds an alarm when a radar object enters the zone. Sentry
mode works with all Garmin GMR model radars.

Enabling Timed Transmit

From the sentry screen, select MENU > Sentry Setup >
Timed Xmit > On.

Setting the Standby and Transmit Times

Before you can set the standby and transmit times, you must
enable timed transmit (Enabling Timed
To help conserve power, you can indicate the radar standby
time and the transmit time to implement periodic radar signal
transmissions at set intervals.
1
From the sentry screen, select MENU > Sentry Setup.
2
Select Standby Time.
3
Enter the time interval between radar signal transmissions.
4
Select Transmit Time.
5
Enter the duration of each radar signal transmission.
or .
Transmit).
Radar