Garmin nuvi 500-Series, Owner'S Manual

Radar Display Modes

NOTE: 

Not all modes are available with all radar devices and all 

chartplotters.
Select 

Radar

, and select a mode.

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

.

Range of Radar Signals

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.

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   or  .
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.

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 Transmit

 > 

On

.

Setting the Standby and Transmit Times

Before you can set the standby and transmit times, you must 

enable timed transmit (

Enabling Timed Transmit

).

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 

Stdby Time

.

3

Enter the time interval between radar signal transmissions.

4

Select 

Transmit Time

.

5

Enter the duration of each radar signal transmission.

Enabling a Guard Zone

From the sentry screen, select 

Menu

 > 

Sentry Setup

 > 

Enable Guard Zone

.

Defining a Circular Guard Zone

Before you can define the boundaries of the guard zone, you 

must enable a guard zone (

Enabling a Guard Zone

).

You can define a circular guard zone that completely 

encompasses your boat.

1

From the sentry screen, select 

Menu

 > 

Sentry Setup

 > 

Adjust Guard Zone

 > 

Move Radar Guard Zone

 > 

Circle

.

2

Select the location of the outer guard zone circle.

3

Select the location of the inner guard zone circle to define 

the width of the guard zone.

Defining a Partial Guard Zone

You can define the boundaries of a guard zone that does not 

completely encompass your boat.

1

From the sentry screen, select 

Menu

 > 

Sentry Setup

 > 

Adjust Guard Zone

 > 

Move Radar Guard Zone

 > 

Corner 

1

.

2

Touch and drag the location of the outer guard-zone corner 

À

.

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Radar