I know it's best to alway fly line of sight. However, where I live we have lots of tall trees and a lot of tidal water via the bay to lots and lots of rivers. So, I fly a lot of the rivers using autonomous flying with my way points. In order to be safe I have to do a lot of checks and calculations. Battery time is a key factor. The other is plotting my course as to keep as clear as I can from objects such as houses, boats docked and other such objects. I have been doing this type of flying for over a year now and I wonder if many of you have to fly waypoint to and your thoughts.