I normally wear 11.5 but chose a size 12 in this shoe because I did not want to risk them fitting too tight. Poor circulation equals cold feet in early spring kayaking. These shoes were fine for walking on slippery mud banks, portaging and carrying a boat on a gravel path, and swimming in fast moving deep water. They never felt too thin or too loose. I'm not sure if they float because they never left my feet. My guess is that they will hold up fine for a few trips, but the thin, light mesh tops and overall construction do not look extremely durable, and once they rip, there is no repairing them. Time will tell.