I've had really good luck with my Kodak Playsport Zx3 with a little magnetic wide angle lens. I mean, it's not perfect, but if you are just interested in filming yourself for instructional purposes, it works great. And with the older model Zx3 you can video all day long with extra batteries and sd cards. At 60fps it gets strokes okay. I hang it on the fence with my little monopod/hanger gadget and get great videos of my matches.