FAQs

We have had many of phone calls lately from users experiencing location issues on their unit. Most have been Lowrance units and we found users have not updated their unit’s software. If you are experiencing any of the following, please follow instructions to correct issues.

1. Waypoints are not correct, positions are off

Have you updated your unit’s software? Most manufacturers provide updates to their units. Updates ensure reliable operation and extend functionality and the life of your unit. If you have never updated your unit, visit your manufactures website and search for Software Updates. To Update Your Unit see the section below.

2. Time and Date is Incorrect

Your unit might be affected by the GPS Week Number Rollover, see the section below for information on this.

3. Waypoint Depths Are Incorrect

If you imported waypoints and the depths are incorrect in your waypoint list, this is normally due to a setting in your unit that needs to be changed from meters to feet.

 

Update Your Unit’s Software

If you have an older unit, you will need a 2GB or smaller chip to transfer the updates to your unit. Do not use a Navionics or other software chip to perform an update as they contain software that will interfere with updating. To reuse a chip, insert it into your computer, copy all data on the chip to your computer if you want to save it, then right click the drive letter for the chip and FORMAT the chip to FAT. If you use a chip larger than 2GB, you should still format it to FAT so it works on an older unit. If your unit does not see the chip you used, then you must find another smaller sized chip.

NOTE: Install updates can wipe out the data on your unit. Do a full backup of your data before updating.

1. Backup your units data.

2. Go to your unit’s manufacturer’s website and search for Software Updates for your model.

3. Download the update file(s) to your computer. Copy the file(s) to a blank chip. If the file is a zip file, extract the file to your blank chip.

4. With your unit OFF, insert the update chip into your unit, turn the unit ON and the update should run. Once done, restart the unit again. If you have more than 1 update on the card, you will repeat this step.

5. Restore your backed up waypoints. If you purchased our memory card, re-import the data from our chip.

 

GPS Week Number Rollover – Units with Incorrect Date and Time

The GPS satellites transmit to users the date and time accurate to nanoseconds. The GPS system first began in 1980 to keep track of the date and time. The date and time is represented by a counter that can only count forward to a maximum of 1024 weeks, or about 19.7 years. After 1024 weeks has elapsed, this counter “rolls over” to zero, then GPS time starts counting forward again.  The first rollover occurred in August 1999. The second rollover occurred on April 6, 2019.

If a GPS device is not programmed to accept this change, after the rollover occurs, an incorrect date and time will be displayed. GPS units use the date and time to timestamp track logs, computer sunrise and sunset, tide current data, waypoint/route creation date, and other functions. Position, velocity, navigation, and all other functionality not dependent on date and/or time will continue to work normally.

 

Rollover Updates for Your GPS Unit or Chartplotter

Garmin: Garmin anticipated the Rollover decades ago and all units should have rolled over correctly. Garmin has not issued any updates.

Humminbird: All units manufactured after the year 2000 will be unaffected by the Rollover. They have not issued any updates.

Lowrance: Many Lowrance models are affected by this Rollover. Lowrance has available updates for your GPS unit on their website. Caution! If you have not updated your unit’s software, first update the unit then apply the Rollover update. Go to http://downloads.lowrance.com/, select your model from the dropdown, go to the Software section to find updates for your unit & GPS Patch file for the Rollover update. Save the files to a 2GB memory card, the smallest card you can find because Lowrance requires FAT formatted chips. If the download is a zipped file, you will have to extract the files before using them on your unit.

Simrad: Simrad tested a wide range of their recreational equipment and confirms that all current generation devices are 100% compatible with the GPS week rollover event. They have found a limited number of older devices that experience issues with the week rollover event. Simrad has updates for these units on this webpage along with a list of all models past & present showing if they have been tested. https://www.simrad-yachting.com/news/gps-week-rollover/ Scroll down the page to see the table of models & links to updates.

Raymarine: All current Raymarine units are not affected by the Rollover, see this notice on their website http://forum.raymarine.com/showthread.php?tid=7453. Legacy products that are affected or will in the future are listed in this PDF document http://forum.raymarine.com/attachment.php?aid=2852. For software update visit http://www.raymarine.com/display/?id=797.