While I haven’t yet used these in the water, I did wear them out and about running errands. My old water shoes were quite uncomfortable, but these seem comfortable enough for every day use. Even though these are listed with US sizes, they appear to actually be EU sizes. I read in a review that someone ordered a few sizes, but two of them (8 and 8.5) were actually a size 39. Since I normally wear an 8.5D in sneakers, I went up to a size 40 (9). Keep that in mind when selecting your size. They will get their first water test next month when I go kayaking at a beach.