This paper reports an eight-year field- and laboratory-based study carried out to compare the performance of two proprietary hydrophobic coating systems (silane- and siloxane-based coatings), designed to reduce chloride ingress and reinforcement corrosion. Their behavior in the laboratory was also compared by using concrete of two different mixes (w/c = 0.40 and 0.65). Tests were carried out on a Portland cement concrete with a w/c ratio of 0.4 and exposed to a very aggressive tropical marine environment (average parameters: T >28o C, RH > 80%, time of wetness > 60%, Cl- > 160 mgm-2d-2). The following tests were performed to characterize the concrete mix both physically and mechanically: Compressive strength (ASTM Standard C 39); Total Absorption and Porosity (ASTM Standard C 642); Capillary Absorption (Fagerlund Technique); Rapid Chloride Permeability (ASTM C 1202). All tests were performed at 28 days of cure.