Compact oxide layers predominantly consisting of zinc oxide naturally grow on zinc upon exposure to a single seawater droplet. SEM and TEM reveal the existence of these oxides beneath the surface, close to the metal surface. EIS demonstrates that these oxides serve as an electrochemical barrier on zinc. The compact oxide immediately above the metal surface is 20-70 nm thick and is undulating in appearance making it difficult to identify crystalline features within. However, the oxide layer above this compact oxide shows a dispersion of a large number of fine-sized voids that cluster in certain areas to form larger voids. (C) 2012 The Electrochemical Society. [DOI: 10.1149/2.075302jes] All rights reserved.