Boonie hat, boonie brim or Boonie is current authorized head gear for military personel. It is a full brimmed hat, and provides limited protection from the sun and rain to the head and neck.
These hats were origionally made popular during the Vietnam Conflict worn by
Special Ops soldiers and LRRP personel. The Boonie hat replaces
the standard Army issue "soft-cap" and the
Marine Corps "cover". Sometimes called a "flop-hat"