Air-sea interaction data from a situation with pronounced unidirectional swell have been analyzed. Measurements of turbulence at three levels (10, 18, and 26 m above mean sea level) together with directional wave buoy data from the site ¿stergarnsholm in the Baltic Sea were used. The situation, which lasted for ~48 hours, appeared in the aftermath of a gale. The wind direction during the swell situation turned slowly within a 90¿ sector. Both during the gale phase and the swell phase the over-water fetch was >150 km. The wind speed during the swell phase was typically 4 m s-1. During the swell phase a wind maximum near or below the lowest wind speed measuring level 10 m was observed. The net momentum flux was very small, resulting in CD values ~0.7¿10-3. Throughout the lowest 26 m, covered by the tower measurements, turbulence intensities in all three components remained high despite the low value of the kinematic momentum flux -u'w', resulting in a reduction of the correlation coefficient for the longitudinal and vertical velocity from its typical value around -0.35 to between -0.2 and 0 (and with some positive values at the higher measuring levels), appearing abruptly at wave age c0/U10 equal to 1.2. Turbulence spectra of the horizontal components were shown not to scale with height above the water surface, in contrast to vertical velocity spectra for which such a variation was observed in the low-frequency range. In addition, spectral peaks in the horizontal wind spectra were found at a frequency as low as 10-3 Hz. From a comparison with results from a previous study it was concluded that this turbulence is of the inactive kind, being brought down from the upper parts of the boundary layer by pressure transport. ¿ 1999 American Geophysical Union