I bought these to hike the Zion Narrows in September. A friend had recommended wearing a neoprene sock to help your feet stay warmer in the river. I picked these up and wore them for both days of our 17 mile hike through the Narrows. The water was about 55 to 60 degrees and I hardly noticed at all. It only felt like a difference of a few degrees to me when I was hiking in the water. My feet stayed perfectly warm. The only thing I did not like is that these socks do have seams, but they are positioned in such a way that the seams are on the sides of your foot, not the bottom or on the toes. I could feel the seams, which I didn't care for, but even after 17 miles of hiking in wet boots I didn't get a single blister from them. I've used them twice now and they are still in great shape.