Curtain sails
A curtain sail is a rarely used form of the square sail .
While with normal square sails for reefing the canvas area is reduced by pulling up to the yard , the reefing with curtain sails is done by pulling together horizontally on both sides in the direction of the mast. In contrast to the normal square sail, the operating crew ( top guests ) do not have to board the ship's rigging.
The curtain sail is also known as a lined brig sail .