New flier here. I have had the P3A for a couple of weeks and have have a half dozen flights under my belt. Yesterday I was doing a few over water flights driving in my truck a couple of miles between 3 different sites. First two flights were flawless. On the 3rd, I had just taken off and luckily, before I got out over the water, the copter started behaving erratically. I noted a compass error in the app. It was bit windy and was quite difficult to land but I did manage without tipping over. I had the VPS off as suggested in several posts here. I think it would have been easier to land if VPS was on, perhaps? I had calibrated the compass just before each of the first 2 flights, but didn't just before the 3rd as I had driven just a couple of miles from the 2nd site and didn't think it was necessary. Thoughts on what could have caused the compass error? I'm taking as a lesson learned and will calibrate prior to every flight going forward.