Floating platform (1) having a flat cover element (2) and a sealing element (3), which is connected to the cover element (2), makes a sealing contact with a liquid surface (4) during operation and encloses a closed cavity (5) together with the cover element (2) and the liquid surface (4) or a bottom surface, in which cavity (5) an overpressure which supports the cover element (2) can be produced by a compressed-air production apparatus (5′), with at least one circumferential wall (6) being provided as the sealing element (3), and having a sealing section (3′) which projects into the liquid during operation.