The MOST important gauge for this pattern is determining your own head size before beginning as this will be the guide as to how wide the crown circle for YOUR hat needs to be. Not hook size, not yarn size, not the number of Rnds shown in the pattern, but your own head size. Pull the tape as tight as you would want the hat to fit. Also remember that this hat flares slightly at the brim.

This is similar to my Shell Brimmed Cloche, but flares away from the head instead of hugging it.