A sailing ship comprises a hard sail assembly. The hard sail assembly comprises a plurality of hard sails of wing-shaped hollow cross section. The hard sails are vertically stacked so that each except the lowermost is received in the one immediately below. The sailing ship further comprises an apparatus for driving the hard sails to move each except the lowermost toward and away from the one immediately below, a post extending vertically to support the lowermost hard sail, and a second apparatus for rotating the post around its longitudinal axis. Overlapping lengths between vertically adjacent hard sails are variably controlled to make the hard sail assembly expand and contract vertically.