I was using my phantom 3 std to help look for a lost dog in a marsh. Reeds were 10 - 15 ft tall. Lost rc contact and drone went it RTH. Unfourtunaly rth is set at 100'. Trees were at 25'. Lost the done. Gave it an all out effort to find it but the mud was waist deep in areas and I couldn't get through. Lesson learned, the hard way. Good news, the dog was finally found!