Just a reminder that where you stand with your DJI makes a difference.  I wanted to film from an aluminum jon boat.  Remembering that you are not supposed to calibrate around metal I tried it on land.  Well, as soon as I took off from the boat there was no ability to hover in place.  Right into "oh crap" mode.  It wanted to fly off to the side and I had to have a friend hand grab it while I brought it down.  I was ready so I really wasn't too worried I could bring it down.  

Don't forget the preflight check everyone.

More  important is to understand that you don't have to calibrate the compass all the time.
Get a good calibrating and stick with it rather than continually recalibrating and risking a bad one when you try it in an inappropriate location.