you can not, probably for just that reason. They would not want you to by a $10 app and be able to replace their $150 map I would think. I like this app because I can look to see where I want to go the night before and get familiar with the area with the google map over lay, then post to FB so in case something goes wrong people know the area I will be at. Also the tides, wind, and current tab is nice too. Oh and the social over lay is nice, have used others hotspot markers with success.