These shoes run extremely large.  When the package arrived, I could tell that someone had tried them on and returned them.  When I put them on my son they were a large, but I didn't want to keep buying new ones throughout the summer, so I kept them.  That was a big mistake.  While my son out grew two different pair of sneakers this summer, he never ended up growing into this shoe.  Any time he tried to swim in water, the shoes would come off.  So, all he could really do is walk to/from the water.  Not exactly what I expected for their use.  The one great feature is the cinch on the ankle of the shoe, which helps stay on the foot.