Measurements from the Dynamics and Chemistry of Marine Stratocumulus experiment have been used to study components of the regional ozone budget. The surface destruction rate is determined by eddy correlation of ozone and vertical velocity measured by a low-flying aircraft. Significant variability is found in the measured surface resistance; it is partially correlated with friction velocity but appears to have other controlling influences as well. The mean resistance is 4190 s m-1 which is higher (slower destruction) than most previous estimates for seawater. Flux and mean measurements throughout the marine boundary layer are used to estimate the net rate of in situ photochemical production/destruction of ozone. Averaged over the flights, ozone concentration is found to be near steady state, and a net photochemical destruction of 0.02--0.07 ng m-3 s-1 is diagnosed. This is an important confirmation of photochemical model results for the remote marine boundary layer. These results should generally be applicable to remote marine regions over the globe although the observed variations give large uncertainties. Ozone vertical distributions above the boundary layer show a strongly layered structure with very sharp gradients. These distributions are possibly related to the stratospheric ozone source, but the process of creating and maintaining them are not clearly discernable. ¿ American Geophysical Union 1989