Blank map. Avoid using internet/data.
Blank map option allows you to see waypoints (including the target one) on a map, but avoid usage of internet data. Map works without any data connection and without mobile signal.
To switch to the Blank map, use map settings button:
And choose Blank map:
Go back and be sure that now nothing in the app will consume even a byte of data from your plan!
Another option to avoid data usage is using offline maps. You can download them via the same map settings screen.