Slow or Missing GPS Acquisition on Garmin Chartplotters

If a Garmin chartplotter is slow or not acquiring satellite signals, there could be a few causes. If the chartplotter has moved several hundred miles since the last time it received satellites or the GPS has not powered on for more than two weeks, the chartplotter loses archival data necessary for satellite acquisition. Typically it takes 3 - 5 minutes to acquire if it's lost archival data or after a software update. Allow the chartplotter to remain stationary after a software update or when the chartplotter has lost archival data. 

To resolve satellite acquisition issues:

• Ensure the chartplotter is using the latest software. See Garmin Marine Device Software Updates to install a software update if necessary

• If the chartplotter is using an internal GPS antenna, make sure it's in an area with a clear view of the sky (e.g., a cabin window). Verify the internal antenna can receive the GPS signal. If there is no suitable mounting location where the chartplotter can acquire satellites, use an external GPS antenna

• If the chartplotter connects to an external GPS antenna:

  • Make sure the antenna is properly connected to the chartplotter or the NMEA network. If necessary, see the GPS antenna installation instructions for connection information and diagrams

  • If using the NMEA 2000 network, verify that the chartplotter detects the antenna: From any page Options > Settings > Communications > NMEA 2000 Setup > Device List. If the antenna does not appear on this list, verify the antenna and NMEA 2000 network installation. NMEA 2000 Troubleshooting

  • If the chartplotter has more than one GPS antenna source, select a different source. See the chartplotter's owner's manual for instructions on Selecting the GPS source

If the above troubleshooting steps do not help to resolve the issue, check the US Coast Guard's Navigation Center for GPS service interruptions.