The implementation of measures to increase the energy efficiency of ships is not so successful as expected. A benchmark is needed to gain insight in the present state of the energy efficiency of ships. That can be used to assess why these measures are less successful as expected and to develop better fitting energy efficiency legislation in the future. Monitoring, Reporting and Verification (MRV) is proposed as benchmark methodology. Ships are required to monitor their fuel consumption and/or carbon emissions on annual basis. MRV is believed to close the knowledge gap of ship specific fuel consumption, the best fitting efficiency technologies for ships, and of split incentives and responsibilities across the total sector. There is a European scheme and a global IMO scheme. The reasons why shipping lacks to implement energy efficiency seems as well apply for the implementation of MRV. Shipping argues there is a knowledge gap for the implementation of MRV. Secondly, the monitoring results will be published. That information is considered as confidential and too sensitive for third parties. This study tries to find an alternative method which serves both goals: 1. fuel consumption/carbon emissions are still fully monitored and reported because the specific maritime contribution to global warming is important to know; and 2. the direct fuel consumption/emissions are disclosed and the results have been made anonymously to meet the industry. The latter is done by searching for alternative methods, proxies, parameters which deliver information about fuel consumptions emissions, but which do not directly link to a vessel or present direct information of the fuel consumption. Based on 1. the identification of parameters which are monitored on board presently; 2. making an inventory of methods to calculate fuel consumption and/or CO 2 emissions; and 3. evaluation of which parameters sensitivity and/or anonymizing apply using existing monitored parameters two alternative methods for MRV monitoring seem to meet both objectives. The method of using on-board monitoring devices is a method which has the potential of qualifying with the objectives of less sensibility and more anonymity. The potential of this method lies in the way that it can determine the efficiency of ships. And efficiency can be shared as function of energy labels which present ranges of efficiencies and thus less sensible data is shared. Emission modelling could also be an alternative. Ship fuel consumption/fuel consumption is monitored via AIS and models. Subsequently, the results are brought to the vessels. The model results are verified by the ships. If the results are in the same order of magnitude, the modelling results will be published and become available to the market. The specific information will be shared confidentially to the relevant authorities. A list of questions is developed as tool to evaluate the potential of alternative MRV methods. Developers are able to proof with help of the list of questions their method is feasible to use as MRV method. Ship owners might want to develop their own way of monitoring. This list question might close their knowledge gap around MRV.