Thanks for the advice. I got a pair of Finis Golden Zoomers for lap swimming, and followed their size chart. They are too tight and uncomfortable, and I can't last more than about 1600 yards in them. Then I take them off and swim breaststroke to give my feet a rest and a chance to recover. Am seriously thinking about getting a Foil, but will follow your advice and buy the next size larger. Better to pad up with socks than to suffer from a fin that is too tight.