Organic coating is an efficient method to protect metal surfaces from corrosive atmospheres but is dependent on the presence of a stable interface between the substrate and the polymer coating. However, coatings based on polymers have mostly only limited barrier properties for water and oxygen. Transport of water to the interfacial region is for most coatings inevitable upon prolonged exposure in aqueous environments. Ingress of water molecules can destabilize the substrate / polymer interface and lead to delamination of the polymer coating and initiation of corrosion processes. In this work was spectrochemical imaging of the substrate / polymer interfacial region using a FTIR-microscope with a focal plane array (FPA) detector is performed in order to follow the water up-take at the substrate / polymer interfacial region with micrometer sized lateral resolution. Chemical imaging of the interfacial region between substrates, such as Ge and Ge with thin Zn metallic layers, and organic coatings was performed during exposure to 0.1 M NaCl and humid air (95 %RH). The water uptake and water induced alterations in the substrate / polymer interfacial region on the microscale was followed. Simultaneous electrochemical impedance measurements allowed correlation of electrochemical information from the coated metal with the chemical imaging of the interfacial region.