If anyone has a quick trick for removing groups of waypoints (based on create date) let me know and I can help my friend here with something. For a Lowrance HDS Gen 3, the only procedure I know is:
1. downloading the data from the unit to a card
2. editing the .GPX file on a PC
3. resetting the unit to purge all data
4. uploading the edited file to the unit
He'll definitely need help on the fishing side if he wants to beat us this month! Heading out on Sunday to see if my areas for quality unders are still producing.