•The rust layer on weathering steel (WS) is stratified in two sublayers.•The inner sublayer is rich in goethite and the outer sublayer in lepidocrocite.•Ni-advanced WS show higher corrosion resistance than conventional WS.•Ni raises the proportion of nanophasic goethite in the inner sublayer.•Ni-advanced WS could be suitable for salinity levels up to 30mgCl−/m2d. One conventional and three Ni-advanced weathering steels have been exposed for one year in two marine atmospheres of moderate aggressivity (30 and 75mgCl−/m2d). The rusts generated have been analysed by polarised light optical microscopy, SEM, XRD, Raman spectroscopy and Mössbauer spectroscopy. The presence of high nickel (1–3% weight) contents in the steel composition leads to higher corrosion resistance in moderate marine atmospheres. The presence of nickel in the weathering steel also raises the proportion of nanophasic (superparamagnetic) goethite in the inner rust layer.