The use of aluminum alloys in drilling riser systems is one method to reduce riser weight thereby allowing a given drilling platform to drill in deeper water than would be possible with a steel riser system. One of the key performance drivers needed for successful implementation of aluminum into riser systems is corrosion resistance. In this paper we will discuss seawater corrosion testing conducted on several candidate aluminum alloys for offshore applications. Samples were exposed in actual ocean-water for time periods up to a year both with and without cathodic protection. Cathodic protection was applied using several different anode types and several cathode/anode area ratios. A sacrificial Zn/Al thermal spray coating was also included in parts of the testing program. Corrosion potentials and the galvanic currents between sacrificial anodes and test-samples were measured. Results will include a summary of the severity of corrosion as a function of alloy and cathodic protection as well as a treatment of the corrosion potential and galvanic current data.