The kybun walk-on-air sole has tiny openings for ventilation that help to dry sweat faster than other shoes. But in general, kybun shoes are not suited for activities that involve water. There's no problem wearing them in rainy weather, but the sole can not be submerged under water as the air tunnels in the sole need to be kept dry.
kybun shoes can be worn in the rain or snow without any problem, but they are not suitable for use in water as the air channels in the sole fill up with water. If water nonetheless gets into the kybun shoe, it must first be shaken out thoroughly, then sucked out using a vacuum cleaner. The shoes can then be left to dry fully at room temperature (sole up). The drying process should not be accelerated artificially (e.g. by means of a hair dryer, heater or dryer), as this will damage the material.