We Used these at the Baths at Virgin Gorda and they were perfect! People with flip flops or barefoot were envious. Good traction, water drains out. Obviously some sand collects as you are submerged due to mesh but you could walk just fine even with sand. They rinse clean quickly.  Very comfy and true to size. My husband wears 10 or 10.5 and has narrow foot. The size 10 fit him perfectly.