This study is part of a Round robin trial conducted by the International Standardisation Organisation (ISO). The study was intended to form a technical background to the revision of the accelerated corrosion testing included in the ISO 12944- series. More specifically, the Round robin trial aimed to investigate the repeatability of accelerated corrosion testing performed at different testing facilities by different testing bodies. The field exposure covered in this report was carried out as an add-on project. The add-on project was initiated to be able to compare the accelerated corrosion testing performed in the Round robin trial with coating degradation in a “real” environment. The field exposure was carried out during four years on the Swedish west coast at RISE testing facility Kvarnvik väst on Bohus-Malmön.