The marine atmospheric corrosion resistance of a variety of metallic, ceramic, and metallic/ceramic coatings on aluminum and steel alloys is investigated to assess the long term protection capabilities of these barrier coatings. Results of 6 to 42 month exposures indicate that the following coatings provide the best marine atmospheric corrosion protection: thermal sprayed aluminum, zinc, zinc-aluminum pseudo alloy, aluminum oxide (Al²O³), and both zinc-based and aluminum-based metallic/ceramic coatings. The application of a low viscosity sealer to one of the ceramic coatings extends the protective capability of the coating.