The waypoints download into any unit, given the correctly formated file. HDS will come in a easygps file and you can download easygps (its free) and look at, add or delete
anything you want. If you have a HB unit, it will come in Humminbird PC matrix file.

The waypoints do not affect how your unit works. It is the same as if you marked the spots yourself. The waypoints are uploaded in the internal memory and any
map data you have will be displayed from the map SD card. If you take the card out, you have no map. The waypoints are stored internally and after being uploaded,
you take the card out and put it in a safe place. The waypoints stay in your unit until you delete the NAV data.

Sorry for the delay in answering the questions. If you have any other question, please go to the website and email me or call me.
I will be fishing or ATV riding this week and not near a computer with internet service.

Thanks again!