The adhesion of a range of organic coatings to various substrates has been measured under service conditions by the torque spanner technique. Measurements, taken monthly over four years, showed that the adhesion of all the systems varied considerably. Primers containing zinc, lead or both were used in all but one of the systems, and that was the only one to show complete failure of adhesion. Observed losses in adhesion could be related to the moisture content -- AATA