A boater (also basher, skimmer, cady, katie, somer, 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 byFBI 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.
Inexpensive foam or plastic skimmers are sometimes seen at political rallies in the United States.
In Australia, New Zealand and South Africa the boater is still a common part of the school uniform in many boys schools, such as Shore School, Knox Grammar School, Maritzburg College, South African College School, St John's College (Johannesburg, South Africa) and Wynberg Boys' High School.
The boater may also be seen worn by the 'carreiros' of Madeira, the drivers of the traditional wicker toboggans carrying visitors from the parish church at Monte (Funchal) down towards Funchal centre.
Being made of straw, the boater was and is generally regarded as a warm-weather hat. In the days when men all wore hats when out of doors, "Straw Hat Day", the day when men switched from wearing their winter hats to their summer hats, was seen as a sign of the beginning of summer. The exact date of Straw Hat Day might vary slightly from place to place. For example, in Philadelphia, it was May 15; at theUniversity of Pennsylvania, it was the second Saturday in May.