The traditional method used to estimate the hydrodynamic performance of a ship uses either the model test results or one of the many empirical methods to estimate and observe the trend in fouling friction coefficient ($\Delta C_F$) over time. The biggest weakness of this method is that the model test results as well as the empirical methods used here is sometimes not well-fitted for the full-scale ship due to several reasons like scale effects and, therefore, this method may result in an inaccurate performance prediction. Moreover, in the case of a novel ship design, it would be nearly impossible to find a well-fitting empirical method. The current work establishes a new performance indicator, formulated in the form of generalized admiralty coefficient with displacement and speed exponents statistically estimated using the in-service data recorded onboard the ship itself. The current method completely removes the dependence on empirical methods or model test results for the performance prediction of ships. It is observed here that the performance predictions using the current method and the traditional method are based on the same underlying logic as well as the results obtained from both the methods are found to be in good agreement.

用于估算船舶水动力性能的传统方法使用模型测试结果或许多经验方法之一来估算和观察结垢摩擦系数的趋势（$\Delta C_F$） 随着时间的推移。该方法的最大缺点是，由于比例效应等多种原因，有时模型测试结果以及此处使用的经验方法不适用于全尺寸船舶，因此该方法可能会导致结果不准确。性能预测。此外，在新颖的船舶设计中，几乎不可能找到合适的经验方法。当前的工作建立了一个新的性能指标，该指标以广义金钟系数的形式制定，其位移和速度指数是根据船上所记录的在役数据进行统计估计的。当前的方法完全消除了对经验方法或模型测试结果的依赖，从而无法预测船舶的性能。