Marine energy is a renewable source that has not been exploited widely. Fetching the off-shore marine energy requires a lot of investments, thus, maximizing the power delivered by the marine current system is important. Marine current power generation may be limited during certain periods due to weather situation and far distance power transmission that makes failure rate arise and repair time long. In this thesis, using marine current speed recorded at Taiwan coastline, we analyze the reliability and not-delivery energy indices of different off-shore power collection topologies and transmission system by using fault tree analysis and network reduction method. Model parameter uncertainty effects on the system reliability are studied and economic assessments of these configurations are also conducted.