My wife has long thick blonde hair and a hat just blows off at any speed over 10 mph, as does mine. Just want her to be comfy and not have to ride holding her hat on with both hands while underway.
For my wife, nothing stays on her head, or fits her well anyway (smaller head, but long darker hair). She just lets the hair blow in the wind. Sometimes she puts it up in a ponytail and that helps.
I don’t think there are real good answers for anything above a slow cruise for anyone with long hair. It is what it is.
With shorter hair, I think a ball cap turned backwards is probably about the only thing that stays on well when going fast, or doing more aggressive water sports. And that typically is not a look most women like…or with longer hair (like my wife), can wear anyway
My wife had a little bout with skin cancer a couple yrs. ago so she's pretty covered up when we go out. Double Bimini, UV shirt and her trusty visor cap!!! The only time she takes it off is when she skis!!!
My wife braids her long blonde hair into pigtails same as when we ride the Harley. No tangles to deal with later this way plus she really looks good! There are also leather wrap covers made for this purpose at any motorcycle accessory store or dealership. Ask the ladies at a Harley dealer how to handle wind.
My wife has long thick blonde hair and a hat just blows off at any speed over 10 mph, as does mine. Just want her to be comfy and not have to ride holding her hat on with both hands while underway.