I always keep a tub of that **** in my jeep. I have never used it on my face on cold days, even though I have though of it. On longer sessions I always use it on the neck, arm pits and crotch of my wet suit to prevent chafing. It works pretty good! It also stays on your skin for a while. Has not ruined my wet suit as far as I can tell, but keeps it nice and slick. It is typically only needed because my wet suit is not new any more. The older the wet suit, the more chafing I seem to get.
By the Way, There has not been a surfable wave in N.H. in the last month, and its seriously depressing.