In sailing, a detachable pole that extends from the mast and attaches to the jib at the clew. Used in running before the wind. Its purpose is to hold the jib out on the opposite side of the mainsail in clean air, producing a greater degree of control and efficiency than could be achieved otherwise. Without a whisker pole, a slight shift in wind can cause the jib to whip behind the main.
The whisker pole acts like a temporary boom to hold the jib out rigidly, in the same way the actual boom holds the mainsail.