This is the thing...all the reviews I read of my current shoes is that they tend to run on the wide side. I tried a pair of Northwaves back in the day, since everyone said they run wide, but found the only thing wide on those to be the heels. I'm guessing all WSD shoes are off the table. A women's medium is a B and I am at least a D width (men's medium -- I even wear men's Nike Free running shoes, because the women's are vise-like), if not a EE. My husband wears a men's 11 (4 full sizes than my sizing in men's shoes) and his foot is only 6mm wider than mine. I have flippers.