The Boatswain's call (or pipe, NEVER "Whistle") dates back to and before the days of wooden-walled ships firing broadsides of round shot, when the Boatswain's Mate was a rough, roaring shellback. It had very definite practical uses in the days of sail. Men high on the royal and top gallant yards could hear its piercing call rising above the decks. In the wind ship days, merchant as well as naval vessels carried piping Boatswain's Mates; but the pipe has long since ceased to be a feature of anything but a man-of-war.
As far as English ships are concerned, the call can be traced back to the days of the Crusades, 1248 A.D. As far back as 1485 A.D, the pipe was used by the English as a honored badge of rank, and was always worn by the Lord High Admiral of England. It was probably worn because it had always been used as a method of passing orders. When the Lord High Admiral of England, Sir Edward Howard, was killed in action off Brest in1513, a "Whistle of Honour" was presented by the Queen Mother of France to the officer who commanded the French Galleys on this occaision. From about that point on it was no longer worn as a badge of rank in England, and it reverted to it's orriginal use and was imployed only as a means of passing orders.