All hands on deck.
When the going was rough, all sailors needed to be on deck, to
man the pumps, go aloft, or in case of war, defend the ship in action. "All hands on deck" was
one of the many special commands blown by Bosun's Mates on their specially shaped whistle,
called a Bosun's call, pipe, or whistle. Sometimes the whistles were blown as a salute, for visiting
dignitaries, for weddings or burials.
For more information about Bosuns calls click