though I would use the wind for lift, so wouldn,t need the motor & could use a lighter battery pack. Have an elevon for up, dn, L, R control. Attach the line at the CG, so it wouldn't pull the nose down at higher altitude. Loops would be tough! On second thought I could use the motor to drive the winch to pull it back down :-). I might not ever get it out of my head & into the air.
I kind of like the boat idea too.

Mike D.