Mission Track Length

I would like to know how to make my boat tracks last longer than few minutes only. I am doing bottom survey with the ArduRover boat and I must have all my tracks visible on the screen in order not to measure something that was already measured few minutes before. Is there any way to leave that purple track line on the screen without erasing it.

This is really a GCS question. Perhaps add a tag for your gcs (Missionplanner/MAVProxy/QGC, whichever you’re using), to increase the odds of the right people seeing this