In fact, Lowrance, Simrad and B&G models automatically store sonar data by default during everyday use, so unless you have turned trails off, the whole library of sonar logs recorded since day one may be residing on the plotter’s memory. All you have to do now is export from your chartplotter to your Navionics card and upload to our website. Once sonar logs are saved on a card, it can be plugged into a computer and the data is transferred to Navionics through the internet to generate new SonarCharts™ for you and other boaters after about one week.
Here is how: http://www.navionics.com/en/plotter-tutorial/lowrance. You can print these instructions before you go to your boat or read them on your phone while you are onboard next to your sonar.
Only Navionics accepts sonar logs from all major brands including most models of Humminbird (DAT and GPX on all models, GPX only on ION and Onix), Raymarine (SDF, NMEA, GPX) and Garmin (ADM). Check http://www.navionics.com/en/compatibility. Boaters can choose to share all of their logs at once or they can record and export specific files. Learn more about SonarCharts™ and find tutorials on how to record sonar logs.
On GPS plotters, it’s included with Navionics+, Platinum+, and HotMaps Platinum for compatible plotters. Owners of any Gold, Silver, Marine & Lakes USA, and HotMaps Premium cards can have it with Navionics Updates.