I usually have narrow, skinny feet, and wear a size 230 in Cortez.
It fits loosely, so I ordered a 230.
As expected, it fits comfortably and is incredibly lightweight.
Due to the nature of the material, it will probably get dirty quickly, but
I was hooked on the white and black combination, so I splurged before the green one came out.
I saw a post saying to size up half a size, so I'm sharing this for size reference.