It stays on, is crazy comfortable, stylish, and you can go anywhere in them. I have a Morton's Neuroma in the ball of my foot, so it is challenging to find sandals that don't constrict across the width of the ball of my foot, yet also aren't a flip flop and require gripping with your toes for them to stay on. I had resolved to buy a pair of Crocs for the ease and slip on-ness and the convenience of a plastic sandal as I am mom, a gardener and live on the coast. Crocs just do not fit me right no matter what size or style, and then these popped up in my amazon suggestions. I just put these to the test on a rocky ocean beach following my 4 year old around, wading, climbing and swimming and not once did I slip, nor my foot slip around in the footbed, nor did I worry that they would come off. And to top it off they look nice enough to wear for almost any occasion, and with almost any outfit. I did order a size down- normally I am a solid size 40 and those were a bit long so I exchanged for the 39 and they are perfect. Also, when ordering somewhere along the line it says that they are narrow width- but this still worked fine for my foot even though I normally need a slightly wider footbed. I bought the anthracite color and they are just gray enough to flatter my fair skin the way true black does not. Couldn't be happier!