» This article's about the hat type. For other things called boater see Boater (disambiguation) A boater (also basher, skimmer, katie, or sennit hat)'s a kind of hat associated with sailing and boating. It's normally made of sennit straw and has a stiff or soft flat crown and brim, typically with a ribbon around the crown, which's often in colours representing a school, rowing crew or similar institution. Boaters were popular as summer headgear in the late 19th century and early 20th century,… (More on Boater)