Will the GPS on my PRO+ or CHIRP+ work if I don’t have a mobile or internet connection?

Yes it will. The PRO+ and CHIRP+ have a built-in GPS receiver that will connect directly to Global Positioning System. Functions that use GPS (like On-shore mode or Boat mode) feature a satellite icon in the corner of the map. When the icon is green, it means your unit has a good satellite connection.

However, mobile data will be needed to load a map of the area you're fishing at. If you're fishing in an area with no cellular (internet) connection, simply download an offline map of that area directly to your phone.