Let's place the water tank on a rotating table. If the rotating cycle is amply longer than the cycle of the waves in the tank, nothing special happens. However, when the cycle of the waves in the tank and the cycle of rotation of the table become closer, waves that are propagated along the walls become clearly visible. Further, the waves are only propagated in one direction keeping the wall to their right. These waves, which are trapped at the wall because of revolution, are called Kelvin waves. In the rotating system, waves with period longer than the inertial period have to lean against walls to be propagated.