An Investigation of the Convergence of Average Peak Accelerations for High-Speed Planing Craft

This paper summarizes the results of an investigation of the convergence of average peak accelerations as more and more peaks are recorded during rough-water trials of small high-speed craft. Existing guidance from multiple sources suggest that more peaks is better, but how much more, and what engineering rationale should substantiate the answer? To address the question, simplified equations and numerous examples of peak acceleration data sets are presented. The results demonstrate that convergence of the average of the highest 10 percent of peaks (A1/10), and the average of the highest 1 percent of peaks (A1/100), and the A1/100 / A1/10 ratio means that the shape of the cumulative distribution of the data set becomes more stable as the number of peak acceleration data points increases. A simple percent-difference criterion is presented for quantifying the stability of the cumulative distribution shape.