Using global satellite Synthetic Aperture Radar (SAR) observations, swell systems are confirmed to travel over very large distances across ocean basins. To yield global and almost continuous coverage of these very well organized wave systems emanating from the different intense storms, a geometrical optics approach is applied. The data are gathered globally and systematically, but the SAR-derived peak wavelength and directional parameters are restricted to the longer swell detected systems for which the SAR-mapping distortion is minimal. Owing to the quality of the retrieved swell parameters, the methodology is shown to provide accurate estimates of the swell arrival times up to 6 days ahead.