"I have a couple of Tilleys and a straw hat but I wouldn't want to lose my Tilleys, and a straw hat looks too hillbilly."
Dave i cannot imagine you wearing a straw hat with a couple of hurricane lamps swinging off the back………….
I have driven with my Tilley when sunny and it felt suprisingly secure and it does have a chin strap.
They do come in different sizes though (heads n hats)
You know it makes sense! 
