>>1093408>Navionics updatesIt depends on the lake. The map data is continuously uploaded from personal sonars, if so enabled, and map uplates are available periodically. So the more expensive fishing boats cruising around your lake the better it will be mapped. Small lakes, or very remote lakes, may not be so precise. In upstate NY where I fish in the fingerlakes, Lake George, Champlain, etc the detail is. Along with sonar, it completely changed fishing for me because of how much I learned from it.
