Inthehostileandhighlycorrosivemarineenvironment,advancedcompositematerialscanbeusedinmarinecurrentturbinesduetotheirhighstrength-to-weightratiosandexcellentresistancetocorrosion.Acompositematerialmarinecurrentturbine(CMMCT),whichhassignificantadvantagesovertraditionaldesigns,hasbeendevelopedandinvestigatednumerically.Asubstantialimprovementinturbineperformanceisachievedbyplacementofaducttoconcentratetheenergy.Computationalfluiddynamics(CFD)resultsshowthattheextractedpowerofaductedCMMCTcanbethreetofourtimesthepowerextractedbyabareturbineofthesameturbinearea.TheresultsprovideaninsightintothehydrodynamicdesignandoperationofaCMMCTusedtoshortenthedesignperiodandimprovetechnicalperformance.