This paper follows two earlier papers, published by the Society in 1962 and 1979, dealing with correlation allowance and design power margin. For some time it has been perceived that a need exists for changes in the numerical quantities which have been specified by the U.S. Navy for correlation allowance coefficients and design power margins. This perception results from the recognition of a growing body of experimental data, both from model experiments and from ship standardization trials, that provide the basis for both correlation and margin policies. In response to this need, an exhaustive investigation was undertaken to establish a sound basis for a revised correlation allowance policy and to evaluate its impact on design power margin policy. The investigation, which led to proposed revisions in both policies, provided the material for this paper. Presented herein are:
a review of the state of the art in the areas of correlation allowance and speed-power margin;
an updated database derived primarily from model experiments and standardization trials of U.S. Navy ships;
an assessment and interpretation of the database;
a proposed alternative to the current correlation allowance policy;
an evaluation of the impact of applying the proposed policy in determining required speed-power margins for U.S. Navy ships; and
a proposed alternative to the current design power margin policy for new U.S. Navy ships.