Abstract: A method for the reduction of ship fuel consumption through the optimisation of vessel draft, speed and trim using historical vessel data. Historical global, online data, is collected for multiple vessel operating parameters associated with its previous voyages. After initial filtering and cleaning of the gathered data, a process of analysing the data to determine the optimum draft, speed and trim for the vessels' given speed is described. The determined optimum draft, speed and trim values are then presented to the Captain or an automatic draft and trim optimisation system for the current draft and trim to be adjusted. This application therefore discloses a method for analysing historical vessel data to provide advice on optimum draft, trim and speed. A method for predicting the achievable fuel savings and recording the fuel savings achieved is also disclosed.