Garmin echoMAP CHIRP 74sv Owner's Manual

• Keep the original sales receipt, or a photocopy, in a safe 

place.

Cleaners containing ammonia will harm the anti-reflective 

coating.
The device is coated with a special anti-reflective coating which 

is very sensitive to waxes and abrasive cleaners.

Apply an eyeglass lens cleaner specified as safe for anti-

reflective coatings to the cloth.

Gently wipe the screen with a soft, clean, lint-free cloth.

You can capture a screenshot of any screen shown on your 

chartplotter as a bitmap (.bmp) file. You can transfer the 

screenshot to your computer.

Insert a memory card into the card slot.

Select Settings > System > Display > Screenshot Capture 

> On.

Go to a screen you want to capture.

Hold HOME for at least six seconds.

Remove the memory card from the chartplotter, and insert it 

into a card reader that is attached to a computer.

From Windows

®

 Explorer, open the Garmin\scrn folder on the 

memory card.

Copy a .bmp file from the card and paste it to any location on 

the computer.

If the device is not acquiring satellite signals, there could be a 

few causes. If the device has moved a large distance since the 

last time it has acquired satellites or has been turned off for 

longer than a few weeks or months, the device may not be able 

to acquire the satellites correctly.
• Ensure the device is using the latest software. If not, update 

the device software (

).

• Make sure the device has a clear view of the sky so the 

antenna can receive the GPS signal. If it is mounted inside of 

a cabin, it should be close to a window so it can receive the 

GPS signal.

Devices erratically turning off or not turning on could indicate an 

issue with the power supplied to the device. Check these items 

to attempt to troubleshoot the cause of the power issue.
• Make sure the power source is generating power.

You can check this several ways. For example, you can 

check whether other devices powered by the source are 

functioning.

• Check the fuse in the power cable.

The fuse should be located in a holder that is part of the red 

wire of the power cable. Check that the proper size fuse is 

installed. Refer to the label on the cable or the installation 

instructions for the exact fuse size needed. Check the fuse to 

make sure there is still a connection inside of the fuse. You 

can test the fuse using a multimeter. If the fuse is good, the 

multimeter reads 0 ohm.

• Check to make sure the device is receiving is at least 10 V, 

but 12 V is recommended.

To check the voltage, measure the female power and ground 

sockets of the power cable for DC voltage. If the voltage is 

less than 10 V, the device will not turn on.

• If the device is receiving enough power but does not turn on, 

contact Garmin product support at 

You can manually enter a waypoint location to transfer and 

share data from one device to the next. If you have manually 

entered a waypoint using coordinates, and the location of the 

point does not appear where the point should be, the map 

datum and position format of the device may not match the map 

datum and position format originally used to mark the waypoint.
Position format is the way in which the GPS receiver's position 

appears on the screen. Commonly displayed as latitude/

longitude in degrees and minutes, with options for degrees, 

minutes and second, degrees only, or one of several grid 

formats.
Map datum is a math model which depicts a part of the surface 

of the earth. Latitude and longitude lines on a paper map are 

referenced to a specific map datum.

Find out which map datum and position format was used 

when the original waypoint was created.
If the original waypoint was taken from a map, there should 

be a legend on the map that lists the map datum and position 

format used to create that map. Most often this is found near 

the map key.

On the chartplotter, select Settings > Units.

Select the correct map datum and position format settings.

Create the waypoint again.

Transmit GPAPB

APB: Heading or track controller 
(autopilot) sentence "B"

GPBOD

BOD: Bearing (origin to destination)

GPBWC

BWC: Bearing and distance to waypoint

GPGGA

GGA: Global positioning system fix 
data

GPGLL

GLL: Geographic position (latitude and 
longitude)

GPGSA

GSA: GNSS DOP and active satellites

GPGSV

GSV: GNSS satellites in view

GPRMB

RMB: Recommended minimum 
navigation information

GPRMC

RMC: Recommended minimum specific 
GNSS data

GPRTE

RTE: Routes

GPVTG

VTG: Course over ground and ground 
speed

GPWPL

WPL: Waypoint location

GPXTE

XTE: Cross track error

PGRME

E: Estimated error

PGRMM

M: Map datum

PGRMZ

Z: Altitude

SDDBT

DBT: Depth below transducer

SDDPT

DPT: Depth

SDMTW

MTW: Water temperature

SDVHW

VHW: Water speed and heading

Receive DPT

Depth

DBT

Depth below transducer

MTW

Water temperature

VHW

Water speed and heading

Appendix

33