Pirate rig was simply anything you wished to wear. It very much depended on where you were serving and the time of year. Some of the items worn would be rescued from the rag bale.
Far east sarong and boots or other footwear, North Atlantic in Winter just about all you could get into. My personal dress was heavy duty surplus tank crew trousers, khaki USN pea jacket swapped for a white woolly poolly, a variety of old and tatty sweaters and checked shirts. One pair of nicks and socks per trip which were then washed or ditched dependent on length of patrol, woolly benny hat or army issued junle hat from Borneo days.
Nutty
PS There was no instruction or order issued after Special Sea dutymen fell out or closed up we just changed from PR to No.8s or the other way round..