I usually wear a size 7.5 so I ordered a size 7.  I started wearing these 3.5 months ago for indoor water aerobics class, 2x/week.  The traction was good until the shoe started to stretch.  Within a month I had to curl my toes to keep the shoes on my feet.  Now the top layers of the insoles have separated from the cushioning.  I'll try gluing them together but doubt that will hold and can only hope the shoes don't stretch any more.  Also, although I regularly rinse the shoes after wearing, the mesh has faded to gray and the ankle trim to beige, leading me to believe the pool chemicals are damaging the fabric strength and durability.