An often underestimated threat to our economy is steel corrosion, in any kind of industry where water meets steel: the maritime sector, ports, water purification plants, energy production, offshore renewable energy production. The costs pertaining to corrosion are immense: a DNV-GL report sets all-round corrosion costs at more than 500 billion EUR for the European region alone, generally +/- 3.8% of the European GDP. However, consultation with industry indicates there is no general approach to determining where and when corrosion is taking place so that preventative and remedial works can be targeted. Solutions are generic, and there is no overall awareness of possible cost reductions: 25-30% of the corrosion-related costs are superfluous – the baseline for the project. The missing step to achieve this is a comprehensive, quick and easy method to measure the local situation in a range of installations and an increased general awareness that costs can be reduced even further.