Through testing under synthetic sea water, seven different copper alloys, namely naval brass and Cu27Zn2.6Pb alloys prepared by extrusion, from squeeze casting, naval brass and aluminium bronze, annealed naval brass and forged aluminium-silicon alloy, were tested in terms of their corrosion resistance, aiming to compare the corresponding behaviour of alloys produced by different metallurgical processes. The corresponding anodic polarisation curves as well as the chemical analysis and the metallurgical structure are shown. The results show a corrosion resistance, in decreasing order of: forged aluminium-silicon bronze, squeeze cast aluminium bronze, annealed naval brass, squeeze-cast naval brass, extruded naval brass, and finally extruded Cu27Zn2.6Pb alloy, demonstrating the role that the processing of a material plays in its final corrosion properties.