Traditional white cotton sailor hat.
The "USN Dixie cap" or the white sailor hat of the U.S. Navy is an iconic headgear that has been part of the uniform of American sailors since 1886. This hat is also known as the "Dixie Cup" because of its resemblance to a disposable cup. It is a white, round, flat flapless hat, originally made of canvas and later cotton, and worn by men in grades E-1 to E-6.
It can be seen in almost every photo of the USN and has been worn by many movie stars in Hollywood, such as "Steven McQueen" in "The Sand Pebbles."