The paper deals with the interaction between Rossby waves and Antarctic circumpolar current (ACC) as viewed by satellite altimetry. We analyze time-longitude diagrams (Hovmollers diagrams) of sea level anomalies for various latitudes of the Southern Hemisphere. The mesoscale eddies are captured by the ACC and propagate to the east along with the general mean flow. North of the boundary of the ACC, mesoscale eddies propagate westward. We calculate the “empirical” velocities of vortex displacement for various latitudes of the Southern Hemisphere using the time- longitude diagrams. We also compute the speed of Rossby waves from dispersion relation of Rossby waves in the long-wave approximation. The result indicates that the theoretical velocities decrease to the Southern pole, and the values of the «empirical» ones first decrease to zero, and then start to grow, changing sign. In the critical layer, the transition of the “empirical” wave velocity through zero occurs, and the position of the critical layer determines the boundary of the waveguide of the ACC. We propose a method for determining the position of the critical layer and the boundary of the waveguide of the ACC by analyzing the Hovmollers diagrams. The obtained approach can be applied to the geographical division of a waveguide.