I’m a stand up surfer and Wanted a hat to keep the chill from getting inside me with wet hair without having to go full on hoodie in early fall. I have a lot of hair and ordered an XL which fits comfortably. I could probably have gone with an L but since you can secure it to your wetsuit in the event it comes off I opted for comfort - plus I’m not usually taking epic falls off my board like prone surfers. Great thing to have in my fall chill quiver. Ordered Saturday and it arrived across state lines on Monday! Crazy quick!