An innovative electrical resistance probe was developed for in-situ, real-time corrosion monitoring of offshore structures, featuring a 1.0 mm track thickness and five sensing tracks. The increased thickness improves compatibility with industrial materials, while the additional tracks provide a more qualitative assessment of non-uniform corrosion. The probe’s performance was evaluated under submerged exposure in natural seawater and across anodic to cathodic potentials, simulating galvanic couplings and varying levels of cathodic protection. Its monitoring results were benchmarked against conventional weight-loss coupons, and the effect of corrosion product accumulation on probe functionality was examined. The probe delivered accurate corrosion rates and confirmed its reliability in natural seawater. The increased thickness extended service life and provided a corrosion-depth sensitivity of 70 nm, while the greater number of tracks brought the exposed area closer to that of coupons, improving detection of non-uniform corrosion. The probe also detected, in real time, variations in corrosion rate caused by interruptions in the cathodic protection system.