The demand for alternative fuels in shipping is steadily increasing, driven by the increasingly strict regulations on emissions. Liquefied natural gas (LNG) is one of the most attractive of these alternative fuels. Not only does LNG reduce emissions of many harmful substances, it can also compete economically with the more traditional fuel oil. Because of this, many new vessels are being designed with LNG in mind. Furthermore, the conversion to a dual-fuel or fully-LNG-powered configuration is being considered for large numbers of vessels sailing today. The conversion of vessels to LNG is a highly interdisciplinary exercise, as it strongly effects the layout, stability, and system routing in the vessel. At DEKC Maritime, our design and mechanical engineering departments have worked closely together on numerous LNG-conversion studies, concerning a variety of different vessel types ranging from open-top cargo vessels to ro-ro passenger ferries. This interdisciplinary approach has provided much insight towards the full implications of LNG conversions.