Dumb question about GPS

I'm going to be installing a new Garmin unit on my boat here pretty soon, I was a big bass fisherman before i bought my new boat. I was running a HDS-7 with the lake chip. My question is, is do i have to have the lake chip in order to mark waypoints or have a trail on my graph?

No, GPS is not mapping and mapping is not GPS.
Mapping is just a background on the plotter view.
The unit does the same GPS functions with or without any background mapping

Thank you, i bought the chip for $100 last time and it does nothing for me. I just want to make sure i can run to my location if i mark it.

You can transfer any waypoints you have from your Lowrance to your new Garmin.