All, thanks for the info. New Question? In my readings, hear and elsewhere, several people have talked about the importance of mast rotation control, especially when using a Spi or hooter. I have very little experence with mast rotators since 99% of my cat experence is on a H16 and 17sport (i.e., no mast rotating systems on these boats). How important is positive mast rotation control? and does it need be incorporated with a Spi/hooter system or is it not really necessary? Thanks