The Duyfken Replica ship visited Newcastle some time ago - where is it these days? The original sailed for the Dutch East India company, round 1606, and sailed not only to Indonesia for spices but ventured south and recorded the first maps of part of the land of Australian.
On that journey the ship sailed in warm waters. No need for the duvet. When the weather is cold enough, as it is right now, many people like to have a Doona as a bed cover. 
Doona is a trade name that has become the common Australian slang description for a quilt with filling.  (So Doona is a form of metonymy).  Derived from the Scandinavian term dyne; popularized by Ikea in the 1970s (Wikipedia). The name, Continental quilt, also became known at one stage.
A Doona has a removable washable cover.  Originally, quilts, which in these parts were often named Eiderdowns, came in floral and coloured fabrics and were stuffed with feathers and eider-down and had the cover and filling stitched together as one. Perhaps the duvet is made the same way and is intended to replace sheets and blankets. The term Comforter is probably not commonly used here.
Koreans and maybe Chinese were seen to favour traditional padded quilts with cotton type covers in yet another style.
Down: the first feathering of young birds. Eider-duck: a north sea duck sought after for its fine feathers.
Wikipedia notes that Duvet Day is used in come countreis to describe on allowance of one or more days a year when employees can simply phone in and say that they are not coming in to work even though they have no leave booked or are not ill.