Heat exchangers are one of the most expensive components in an Ocean Thermal Energy Conversion (OTEC) power plant. Proper heat exchanger selection is crucial to the economic viability of OTEC. Heat exchanger development must balance size, cost, and performance. To meet this goal, the OTEC Heat Exchanger (HX) Testing Program is divided into three areas: HX Performance Testing, HX Design Development, and Corrosion Testing. This annual report summarizes the activities from October 2011 to February 2013 and summarizes the completion of the Phase 3 Milestones.