The increase of marine shipping industry leads to search for the use of clean source of energy such as natural gas to use in the primary propulsion systems. The LNG propulsion systems have been applied for years in different disciplines. Recently, the same are reused with the modern technologies and improvement. Over the years the steam turbine propulsion proved to be the dominant type of propulsion system used in Natural Gas Carriers, even though this system has been for years there was always the need to search for further improvements with the main goal to meet the mandatory requirements of the International Marine Organization. The current trend in the market is the implementation of a waste heat recovery system with dual fuel diesel engines with two main goals, first is to reduce the emission and second is to increase the overall efficiency. The current study is concerned with seeking further improvements that coincide with the market trend, thus a proposed system of a dual fuel diesel engine with a waste heat recovery system implemented is studied to investigate the possibility of those improvements and compared with the available propulsion systems.