This study investigates the feasibility of a hydro powered turbine being implemented behind sailing yachts to meet their daily power requirements. The focus of the study is on the use of realistic model simulations and expansion of previous knowledge and experimental investigation to assess a helical turbine design and performance. The technical design goals of this project are a daily power output of 2.4kW while maintaining an efficiency of 30% for use in varying flow speeds of 1 to 6m/s. After assessing the characteristics of current turbine designs on the market today the Gorlov helical turbine was selected for its increased efficiency, lower torque pulsations, lower self-start speeds and a higher power output capabilities. The following design parameters of the turbine will be maximised for optimum efficiency, blade profile, solidity ratio, number of blades, helical pitch angle and strut design. Experimental tests were going to be conducted to investigate the axis orientation affects, turbulent flow behaviours, flow speed increases and solidity ratio effects. However these parameters were not able to be tested experimentally due to budgeting restraints of the project. An alternative approach using stream tube models and blade element theory to assess the performance of the turbine in relation to these criteria was examined. Previously conducted experimental tests were researched to give another alternative to the experimental investigation. This also provided a comparison to check the accuracy of the mathematical models being used. The final design simulations using models and researched experimental data provided a turbine efficiency of 30% however the daily power production even in ideal conditions was only 804W which is not enough to supplement the daily power required on board a boat. Therefore this turbine was deemed to be inappropriate for this application.