Garmin echoMAP CHIRP 74sv Owner's Manual

You can enter a keel offset to compensate the surface reading 

for the depth of a keel, making it possible to measure depth from 

the bottom of the keel instead of from the transducer location. 

Enter a positive number to offset for a keel. You can enter a 

negative number to compensate for a large vessel that may 

draw several feet of water.

Complete an action, based on the location of the transducer:
• If the transducer is installed at the water line 

À

, measure 

the distance from the transducer location to the keel of the 

boat. Enter this value in steps 3 and 4 as a positive 

number.

• If the transducer is installed at the bottom of the keel 

Á

, 

measure the distance from the transducer to the water 

line. Enter this value in steps 3 and 4 as a negative 

number.

Select Settings > My Vessel > Keel Offset.

Select   or   based on the location of the transducer.

Enter the distance measured in step 1.

Before you can set the water temperature offset, you must have 

a NMEA 0183 water-temperature sensor or a temperature-

capable transducer to measure water temperature.
The temperature offset compensates for the temperature 

reading from a temperature sensor.

Measure the water temperature using the temperature sensor 

or temperature-capable transducer that is connected to the 

chartplotter.

Measure the water temperature using a different temperature 

sensor or a thermometer that is known to be accurate.

Subtract the water temperature measured in step 1 from the 

water temperature measured in step 2.
This is the temperature offset. Enter this value in step 5 as a 

positive number if the sensor connected to the chartplotter 

measures the water temperature as being colder than it 

actually is. Enter this value in step 5 as a negative number if 

the sensor connected to the chartplotter measures the water 

temperature as being warmer than it actually is.

Select Settings > My Vessel > Temp. Offset.

Enter the temperature offset calculated in step 3.

If you have a speed-sensing transducer connected to the 

chartplotter, you can calibrate that speed-sensing device to 

improve the accuracy of water-speed data displayed by the 

chartplotter.

Select Settings > My Vessel > Calibrate Water Speed.

Follow the on-screen instructions.
If the boat is not moving fast enough or the speed sensor is 

not registering a speed, a message appears.

Select OK, and safely increase the boat speed.

If the message appears again, stop the boat, and ensure the 

speed-sensor wheel is not stuck.

If the wheel turns freely, check the cable connections.

If you continue to get the message, contact Garmin product 

support.

Select Settings > My Vessel > Fuel Capacity.

Enter the combined total capacity of the fuel tanks.

You can synchronize the fuel levels in the chartplotter with the 

actual fuel in the vessel when you add fuel to your vessel.

Select Gauges > Engine > MENU.

Select an option:
• After you have filled up all the fuel tanks on the vessel, 

select Fill Up All Tanks. The fuel level is reset to 

maximum capacity.

• After you have added less than a full tank of fuel, select 

Add Fuel to Boat, and enter the amount added.

• To specify the total fuel in the vessel tanks, select Set 

Total Fuel Onboard, and enter the total amount of fuel in 

the tanks.

You can configure the upper and lower limits and the range of 

desired standard operation of a gauge. When a value exceeds 

the range of standard operation, the gauge becomes red.
NOTE: Not all options are available for all gauges.

Select a gauge.

Select Gauge Limits > Custom > Edit Limits.

Select an option:
• To set the minimum value of the standard operating 

range, select Rated Min..

• To set the maximum value of the standard operating 

range, select Rated Max..

• To set the lower limit of the gauge lower than the rated 

minimum, select Scale Min..

• To set the upper limit of the gauge higher than the rated 

maximum, select Scale Max..

Select the limit value.

Repeat steps 4 and 5 to set additional gauge limits.

NOTE: Some settings and options require additional charts or 

hardware.
Select Settings > Communications.
Serial Port 1: Sets the input/output format for the serial port to 

use when connecting the chartplotter to external NMEA 

devices, computers, or other Garmin devices.

NMEA 0183 Setup: Sets the NMEA 0183 sentences the 

chartplotter transmits, how many digits to the right of the 

decimal point are transmitted in a NMEA output, and how 

).

NMEA 2000 Setup: Allows you to view and label the devices on 

the NMEA 2000 network (

).

Marine Network: Allows you to view the devices with which you 

are sharing maps, sonar, or radar. Not available on all 

chartplotter models.

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Device Configuration