In a recent paper (Monaldo, 1988) I presented spatial spectra of wind speed and significant wave height (SWH) variance. The spectra were calculated from spatial variations of wind speed and SWH as measured by the Seasat and Geosat radar altimeters. It has recently come to my attention that these spectra were incorrectly calculated. The shape of the corrected wind speed variance spectra no longer agree with theoretical predictions by Thompson (1973). The expected differences between two altimeter wind speed or SWH measurements separated a given distance apart were calculated in the time domain and not by inverse Fourier transformation of the spectra. The expected differences given by Monaldo (1988) are therefore unaffected by the errors in the calculation of the SWH and wind speed spectra. ¿ American Geophysical Union 1990