I'm hoping someone can help me understand why my Phantom behaved the way it did during my last flight. You'll see at 1:17 in the video where my gimbal makes a strange movement suddenly. I thought for a second that a prop came off! Of course it happens for the first time while I'm over a mile off shore.. I would have liked to get some better shots of the ferry, but I took too long to launch because my compass was detecting abnormal conditions. All was fine after calibrating the compass. I'm wondering if there might have been HV power lines buried directly under where I was launching from. My previous compass calibration was done only a few miles away.