(29)Proper enforcement of the obligations with regard to the sulphur content of marine fuels is necessary in order to achieve the aims of this Directive. The experience from the implementation of Directive 1999/32/EC has shown that there is a need for a stronger monitoring and enforcement regime in order to ensure the proper implementation of this Directive. To that end, it is necessary that Member States ensure sufficiently frequent and accurate sampling of marine fuel placed on the market or used on board ship as well as regular verification of ships' logbooks and bunker delivery notes. It is also necessary for Member States to establish a system of effective, proportionate and dissuasive penalties for non-compliance with the provisions of this Directive. In order to ensure more transparent information, it is also appropriate to provide that the register of local suppliers of marine fuel be made publicly available.