A corrosion monitoring system is developed to determine the corrosivity of naval environments. It consists of a sensor (dissimilar bimetallic couples) and a galvanic current recording system (zero resistance ammeter). The data recording equipment is designed to monitor shipboard environments continuously on a long-term basis. Initially, a database was created from these sensors using accelerated laboratory environmental chambers. Corrosion monitor data, recorded on naval ships and aircraft carriers during their deployment at sea, are analyzed and assessed with respect to the laboratory database. The results show a direct relationship between the sensor output and the corrosivity of the constituents present in the environment.