Laboratory experiments with seawater mimics suggest ozone deposition to the surface ocean can be a source of reactive carbon to the marine atmosphere. We conduct both field and laboratory measurements to assess abiotic VOC composition and yields from ozonolysis of real surface seawater. We show that C₅–C₁₁ aldehydes contribute to the observed VOC emission flux. We estimate that VOCs generated by the ozonolysis of surface seawater are competitive with biological VOC production and emission.