Corrosion protection coating systems for offshore wind power constructions were subjected to offshore conditions on a test site in the North Sea. The systems included organic coatings and duplex (spray metal and organic system) coatings. Special exposure specimens were designed and manufactured and exposed to an offshore environment for three years in order to evaluate their protection performance. The adhesion in terms of pull-off strength and fracture mode was measured on coatings in the underwater zone and in the intermediate zone. All samples met the requirements for offshore ageing in terms of adhesion. An adhesion-based “corrosion protection effect” (CE) is introduced and calculated for the coating systems.