The International Maritime Organisation (IMO) has set the goal to reduce the total annual greenhouse gas emissions from international shipping by at least 50% by 2050 compared to 2008. For this reason, shipowners will have to innovate the drive-trains and energy systems of their vessels to reduce harmfull emissions. To achieve this goal, solutions must be found to store large amounts of cleen energy on board of ships and convert the chemical energy in an efficient way with these drive-trains. Hydrogen is considered as a promising solution for this. However, storing hydrogen is complicated and requires much volume. To overcome this barrier, hydrogen can be stored in dense hydrogen carriers (DHCs). This thesis will perform a technical and economical feasibility study of dense hydrogen carriers as a fuel to power a semi-submersible offshore crane vessel. The Sleipnir, the largest crane ship in the world, is the main subject of this thesis. The objective is to evaluate the technical and economic feasibility of hydrogen based fuels for semi-submersible offshore crane vessels and their impact on the drive-train design. This will be done by designing a new drive-train that can deliver 6.5MWelectricity to power the ship’s hotel load.