As for galvanic corrosion, zinc is not compatible with copper or iron, so zinc is usually installed with a decent slope in order to drain water that might contain trace copper or iron residue. Obviously it is important not to allow contact between zinc and any metals that are at the opposite end of the galvanic chart.
According to VM ZINC, Zinc is highly corrosion resistant in marine environments as well as inland. Regardless of location, erosion rates of the metal are relatively similar. In marine environments, zinc combines with salt in the air mainly to form zinc oxychloride (Zn2 O Cl2). Water soluble and not very adhesive, th