The process of decommissioning ships, usually followed by ship scraping, is associated not only with significant costs but also with many environmental and toxic hazards. Thus, re usability of such ships will offer more advantages than recycling its steel. This paper proposes reusing a post-service life vessel by converting it into an Ocean Wave Energy Device. A systematic study on the preliminary estimation of energy extraction levels from ocean waves is presented, with some discussion on the energy of a ship-shaped body in motion in irregular seas. Heave motion was found to be more favorable for such applications. Thereafter concept designs have been proposed for the device, and the designs have been analyzed in terms of the extent of relative motion and power that could be obtained from each of them. Numerical simulation techniques have been used to generate the results. Through this analysis, it has been established that the idea of constructing such a device is feasible. The relatively slower but high-force systems can use a hydraulic take-off unit instead of electrical inductance generators. The mooring system has also been identified as a separate design problem. Further design issues including optimizing the different parameters, cost analysis and fabrication issues have not been considered — this work is aimed to provide the starting point of the design exercise.