The aim of this study is to assess the main factors that affect the behaviour of carbon steel and galvanised steel in tropical and non-tropical marine environments, identifying those factors that directly affect the behaviour. The results from the INNOVA (Chile) and MICAT/PATINA (Venezuela) projects will be used. These projects evaluated metals exposed to different marine environments using procedures outlined in ISO 9223/9226. The results show that temperature has no significant effect on the behaviour of the materials at the study sites in question (Venezuela being 10 °C warmer than Chile), independent of the tropical nature of the exposure environment, while it is precipitation (>600 mm) and chloride and SO2 content in the environment that mainly influence the behaviour of the carbon steel and the galvanised steel. In addition, an artificial neural network was generated to evaluate the corrosion rate of the studied metals, using meteoro-chemical variables. The neural network for the carbon and galvanised steel was more precise for the exposure sites located in Chile.