OK I learned the hard way. I now know that you need to save your waypoints to an SD chip before you download a new update to your DF.( Ihave an Elite 7 HDI). Yes I lost all my waypoints.

My question is...When I save the WPs to an SD chip, can I use the same chip to download the Lowrance update and then put the chip in the DF and do the update and then save my WPs or do I have to use 2 separate "clean" SD chips??