I made some, non-architect designed (do architect's actually design anything?), modifications. I drilled some small holes in the palstic buckle and stiched it in place to stop the buckle rotating. I also used it with my long sleeved wetty and it stayed put - so I'm not sure whether it was one of these factors or a combination of both that made it work. So I'll be good for the winter.
I like qldsalty's idea of putting it on the mast, is there any impact probability where you have it? how about posting a pic ?