A previously developed first-principles-based equation for potential attenuation along marine pipelines and risers with multiple, equally spaced, identical galvanic anodes was modified to accommodate an error in its derivation. Both the original and modified equations account for the electrolyte (anode), coating, polarization, and metallic path resistances and, as such, represent improvements over previously available representations. Coordinate mapping-based finite difference method (CoMB-FDM) solutions are presented; and to the extent possible, accuracy of the proposed modified equation is verified.