Furuno GP-33 - Manual (Page 25)

2. PLOTTER DISPLAY OVERVIEW
2-5
Note: To cancel, select [No] at this step.
7. Press the MENU/ZOOM key twice to close the menu.
2.6.2 How to erase all tracks
1. Press the MENU/ZOOM key twice to show the main menu.
2. Select [Tracks], and press the ENT key.
3. Select [Delete], and press the ENT key.
4. Select [All], and press the ENT key.
5. Press W to select [Yes], and press the ENT key to erase all tracks.
[Track Memory Used] on the Tracks menu shows “0%”.
6. Press the MENU/ZOOM key twice to close the menu.