I haven't taken these into the water just yet, but wanted to comment on the size for others who are looking. I normally wear a U.S. women's size 7.5 to 8 in shoes. Assuming I would want a snug fit for water shoes I sized down to the 7s in these and they were very loose which would have caused a lot of drag and slipping walking on river beds and such. I received the 6 today and they feel like a perfect fit, snug enough that I am hopeful they'll maintain this comfort when wet. These are shown as women's sizes, but as I wear a 6 in men's athletic shoes, I'd suggest just buying whatever your men's equivalent size would be...<br /><br />I will try to update once I wear these out but so far I'm pleased now that I have found the right fit.