Vertical lines on video

Question

My family does a bit of water skiing and when recording on my gz-MG50AA recorder, playback has fine vertical lines which are very distracting and make the picture blurry. I have tried all the settings I can think of without any success. At the moment I'm getting much better quality video with my fuji digital camera than the camcorder, which sort of defeats the purpose of having it! Any tips please?