This is the dataset supporting the manuscript: Propagation and Dissipation of Southern Ocean Swells: A CFOSAT SWIM-Based Analysis. Results of swell track from NDBC to SWIM together with results of swell trajectories for dissipation calculation are uploaded. S00 to S04 corresponds to 4 steps in mythology. S_calcu is used for dissipation and attenuation calculation. It should be changed when extract the spectral width. S_fig7_8 is used for fig7 and fig8 after the calculation.