To identify and document challenges for the marine industry facing future European regulation of sulphur content of marine fuels. Impact on the supply and demand balance, product mix and cost for the marine bunker market will be assessed. Need for new fuel quality standards will be analysed. Technical and operational constrains and benefits from change of fuel qualities will be investigated and technical and operational impact for engine manufacturers and ship owners presented. Technical limitations for marine engines and potential compatibility problems related to new fuel blends will be particularly considered. A recommended best practice for implementation and control of compliance of new sulphur content regulations for marine fuels will be prepared.