You can record freely as you go about your day! For best sonar log recording, we suggest you keep your speed under 6 knots, although maximum logging speed may vary depending on which device you are using; perform a grid pattern where the distance between tracks is no more than 50 meters /150 feet; and save about every 30 minutes to reduce any risk of loss.
Make sure your MSD/SD card is inserted into your GPS chartplotter and press & hold MENU.
Tap NMEA 1
Tap Start Recording and begin navigating.