I normally wear a men's size 9 1/2, but even after reading all of the reviews, I wasn't sure about what size to get, so I contacted the Get Wet Store. They answered quickly and recommended a size 9, which fits perfectly.  They seem to be just the thing for snorkeling and water sports.  The only thing that I noticed is that as soon as I put them on, my feet got hot, so I would not wear them out of the water on a warm day.  I am glad that I got them and didn't have to pay $30 or more like the other water shoes that I saw.  I will update my review after I have put them to the test, but they look like a winner.