My wife and I were in our Hot Tub on Friday 4/26/2013. It is a Coleman Hot Tub we have had since 2006. When I got out and was drying off I leaned in and touched the water with my hand and got shocked. I tried it again to make sure it was not a reflex and yelled at my wife to get out immediately. I immediately disconnected the power and have just back to it today.
I removed the side cover to the hot tub and took the cover off of the control unit and where the heater is located. One of the studs had rusted almost lose and looks as though it had been oxidization.
I have never known hot tubs to do this in the past and thought that my GFI should have shut it down.
I have attached a photo.