I have north wave celsius too and they are warm and waterproof. I got mine 14 months ago and used them winter and right through summer. I went out a few weeks ago when it had been pouring down for ages and my socks got wet so i bought some gore-tex waterproofer and put it on and they are cock on again good for another year and the spary was only £5 too. RECOMENDED. Im a size 11 too but i got 46 and they fit as i only wear normal sports sock with them so there is plenty of room for me.