The
mast of a
sailing vessel is a tall
spar, or arrangement of spars, erected more or less vertically on the centre-line of a ship or boat. Its purposes include carrying
sail, spars, and
derricks, and giving necessary height to a
navigation light,
look-out position,
signal yard, control position,
radio aerial or
signal lamp. Large ships have several masts, with the size and configuration depending on the style of ship. Nearly all sailing masts are
guyed masts.