In this study, homogeneous calcareous deposit films were formed via electrodeposition, and the characteristics of the films were studied using various surface analytical techniques. In addition, the optimal conditions were determined, and the anti-corrosive effect was confirmed via electrodeposition to form uniform and compact aragonite films in marine environments such as submerged and tidal zones. The calcareous deposit films formed in the tidal zone were thinner compared to those formed in the submerged zone. However, the aragonite–CaCO3 ratio in the tidal zone was high and the films were firm and dense. The adhesion properties were excellent at 3 and 1 A/m2, and the current density was reduced by more than 90% because the films were formed on the steel surface.