Abstract: In appliances for practicing aquatic sports with water flowing upwardly over a sloping bottom surface a premature breakdown of the flow caused by the accumulation of portions of water slowed down by friction at the boundary faces is prevented by at least partially removing said portions of slowed down water. This can be done by sucking off at least the increasingly portions of slowed down water which are preferably refed to a return pipe of the appliance. A further possibility provides that portions of slowed down water are accelerated by supplying water at an increased flow rate. Suction of the portions of slowed down water as well as the supply of water at an increased flow rate is particularly effected through apertures in the bottom surface in the regions in which the portions of water are particularly slowed down, i.e. above all in the regions in the vicinity of an overflow at the upper end of the sloping bottom surface.

Abstract: A water sports apparatus, for simultaneous practicing of a number of types of water sports, being a container having an inclined floor surface and closable lower supply nozzle. Water shooting upwardly over the floor surface flows over an overflow into a supplementary pool which is subdivided into two regions, between which regions is placed a grate, and preferably, on the downstream side of the grate, a backflow valve. On the end of the inclined floor near the supply nozzle is placed an elevated water container, the water from which enables starting of the supercritical torrential flow, until a water quantity necessary for circulation and having sufficient velocity is returned through a return line from the region of the supplementary pool farthest away from the overflow. The region of the supplementary pool near to the overflow enables the athlete to exit from the apparatus without influencing the supercritical torrential stream in the water container.