Forces on sails apart, which generally prevents heeling. Each sailing craft is a system that mobilizes wind force through its sails—supported by spars and rigging—which provide motive power and reactive force from the underbody of a sailboat—including the keel, centerboard, rudder or other underwater foils—or the running gear of an ice boat or land craft, which allows it to be kept on a course. Without the ability to mobilize reactive forces in directions different from the wind direction, a craft would simply be adrift before the wind. Accordingly, motive and heeling forces on sailing craft are either "components of" or "reactions to" the
Scarlet Sails (tradition) of free entertainment provided by the city of St. Petersburg. Entertainment also includes appearances by popular rock-stars, as well as the St. Petersburg Symphony Orchestra, ballet and other classical acts, performing on several stages simultaneously during the event. The show also includes a series of large-scale events on the waters of the Neva River, such as rowing and motorboat races and a massive battle with pirates culminating in the appearance of a tall ship sporting spectacular scarlet sails. The show has become the main part of the White Nights celebration. The 1961 release of the film "Scarlet Sails" boosted the