Balloons and kites may be used for observation (visual and meteorological) and communication (antenna-lifting) purposes. For these purposes, it may be necessary for the vehicle to stay in one place.
Unlike a sailing ship, a free balloon cannot sail in any direction other than directly downwind (sailing ships take advantage of the balance of aerodynamic and hydrodynamic forces to sail offwind). The most that a free balloon pilot can do is to take advantage of the variation of wind direction with altitude. Hence, unless there are special weather conditions (like the "Albuquerque box"), a free balloon cannot maintain station . . .