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Garmin Wind Listing Same Speed for TWS & AWS Underway
Basic Troubleshooting
If True Wind Speed (TWS) and Apparent Wind Speed (AWS) are displaying the same speed while the vessel is moving. It is highly likely the speed sources are not set correctly, have changed, or a device in the system is not functioning properly. It is important to check devices and the connections before making changes to settings.
Physically check the wind transducer, paddle wheel, Airmar DST transducer, Nexus® marine instrument Mast cable, or gWind™ wind sensor wireless connections
Update software
Check the NMEA 2000 device list and reset NMEA 2000 backbone
NOTE: The GST™ 43 speed and temp transducer will display on the NMEA 2000 device list as a GST™ 10 speed and temp transducer.
True Wind Direction (TWD) - The true direction of the wind relative to North
Apparent Wind Angle (AWA) - The angle of the wind relative to the bow of the vessel
True Wind Speed (TWS) - The true wind speed relative to the vessel
Apparent Wind Speed (AWS) - The measured speed of the wind as it is approaching the vessel
Speed Over Ground (SOG) - derived from GPS. The actual speed of travel, regardless of the power source (wind or motor) or the course steered and any temporary variations in heading
Boat Speed (BSP) and Speed Through Water (STW) data comes from a Paddle Wheel transducer. BSP or STW is the speed of the vessel relative to the vessel travelling through water
Speed Source - Is a functional setting to allow the system to use either Speed Over Ground (SOG) or Speed Through Water (STW) to compute the wind values. Users must decide if they want the speed source computation based on the SOG or STW device. Use the Preferred source page to set the device used for calculations or for display
Preferred Source - is a specific data source that supplies information to the display. Users will select the device the data source is coming from
After checking physical connections, devices show on the NMEA 2000 device list and wind data is present check settings beginning with Speed source settings.
Speed Source Settings
NOTE: If the vessel has an Autopilot system, do not change the speed sources settings for the Autopilot system.
If the Speed Source is not correct, the True wind values and Apparent wind values will show the same data. The calculations are missing the BSP or SOG thus showing the same wind values. A vessel needs at least one of these values for the formula to be complete, allowing the True Wind values to display.
What is the source that is currently selected? BSP, STW or SOG
If the vessel has a paddle wheel
Select the BSP or STW as a Speeds Source
Set the Preferred source as WIND rather than GPS
If the vessel does not have a paddle wheel
Select SOG (GPS) as the Speed source
Set the Preferred source as SOG (GPS)
- If the vessel does not have a paddle wheel the GPS (SOG) will be the only speed source available
TWS is a calculated value and would give a wind value as if the vessel were not moving. If the vessel is stationary the Apparent Wind and True Wind values are the same.
Example of BSP vs SOG:
The vessels engine is off and drifting in the water with a three knot current.
The vessel will have zero knots BSP or STW, but will have three knots SOG Because the BSP or STW source is a Paddle Wheel and the Paddle Wheel is not spinning. Conversely, the SOG source is GPS and the boat is moving with the three knot current across the face of the Earth.
When Speed Source is set to Auto, the display will choose the speed source to calculate the True Wind Formula. The display will first look for a BSP or STW option on the NMEA 2000 data sources as defined in the Preferred Sources option. If no BSP or STW option is available, the display will choose and display the Speed Over Ground (SOG) for that display.
GPSMAP® chartplotters
On Current GPSMAP models: Options > Settings > Preferences > Navigation > Speed Sources > True Wind Select the appropriate speed source, power cycle chartplotter (off and back on to save the setting).
Legacy GPSMAP: Settings (Configure) > Preferences > Navigation > Speed Sources > True Wind > Select the appropriate Speed Source
ECHOMAP™ chartplotters
ECHOMAP UHD2 series, ECHOMAP Ultra 2 series: Options > Settings > Preferences > Navigation > Speed Sources > True Wind Select the appropriate speed source, power cycle chartplotter (off and back on to save the setting).
ECHOMAP PLUS series, ECHOMAP UHD series, ECHOMAP ULTRA series: If the home screen on the ECHOMAP unit does not have a Wind Gauge create one. From the HOME screen on the ECHOMAP press Menu > Compass Gauge > Speed Display > Select the correct speed source (GPS or Water Speed) Use the power button to cycle power (off and on) this saves the settings on the device.
GMI™ 20 marine instrument
Begin on the Home page select the center button (three lines) > Set Up > System > Speed Sources > Wind > Select GPS Speed > select the appropriate Speed Source (GPS, boat, Auto). Use the power button to cycle power (off and on) this saves the settings on the device.
GNX™ 20
marine instrument
| GNX™ 21 display | GNX™ 120 display | GNX™ 130 display
The GNX display must be on a type of True Wind data page for example TWA, TWS, or TWD
Begin from the True Wind Data page, press the center button with the three lines select > Configure Data Fields > True Wind Data > Speed Sources > Select the appropriate source (SOG, BSP, Auto). Use the power button to power cycle (off and on) this saves the settings on the device.