@Big J the deck jackets were made to fit comfortably over Navy dungarees (the traditional working uniform aboard ship). The chambray shirt was relatively thin but in cold weather was worn with a black "Gob" sweater that was thick wool with a mock turtleneck design. Perhaps the roomy fit of the N-1 was to facilitate some freedom of movement for line handling, climbing ladders, slinging and rigging, painting, boat driving, and any other duties performed by Sailors in the Deck Division.