A boater (also basher, skimmer, katie, or sennit hat) is a kind of hat associated with sailing and boating.
It is normally made of sennit straw and has a stiff or soft flat crown and brim, typically with a ribbon around the crown, which is 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, and were supposedly worn by FBI agents as a sort of unofficial uniform in the pre-war years. Nowadays they are rarely seen except at sailing or rowing events, period theatrical and musical performances (e.g. barbershop music) or as part of old-fashioned school uniform, such as at Harrow School.
