Fits my relatively narrow to medium foot snugly in the Bass Pro Shops Redhead Wool Blend Wool Blend Socks. The ones with a lifetime warranty sell for $10-13. This water shoe is very comfortable at home and at the gym. This week I'm taking it and going into the brackish backcountry. Like a kayaker, these shoes get wet from lots of salt and sun. Hopefully the upper stays intact and the glue keeps the sole in place. The time will show. I like the lacing system more than the bungee system to keep the shoe on the foot. The laces could be a bit longer as they are long enough to tie a knot. Wide feet and these shoes are probably narrow and the laces are too short.