Abstract: The floats (1) of the device for water-sports can be used as water-skis and have practically trapezoidal cross-section over their whole length. To achieve optimum linear running stability, especially when using the float as a water-ski, it is tapered from back to front, both in plan and side view. To achieve good tread resistance or running depth stability when walking on the water, the bottom of the float is flat or slightly concave over practically its whole length. The floats can be constructed as self supporting, foam plastic bodies with water-tight closed surface pores or as integral or multiple-piece molded hollow bodies.