Approximately 10,000 changes a week. this is a total number so I can’t give you a complete breakdown by area. These are daily updates though. This could include new Community edits, updated one foot contours, underwater structures or new lakes we release as we get them. This again doesnt include SonarCharting.rnrnto get it, when you buy your chip (or if you already have one) register it online with our website within 60 days. go on anytime after that whenever you want, plug in your chip, and get the free update through our webstore. this is a brief video to help youif you have any issues please let me know,just make sure your chart is new or within the last two years. if it is within the last two years and past the 60 days you can renew it for $99 rather than buy a brand new chart at full price. save some money