A Simplified Power Estimation Method for Monohull High-Speed Small Craft

Abstract

This paper presents a summary of the results of a study of the parametric interrelationships between size, weight, hull proportions, propulsion power, and craft speed of modern, high performance, monohull marine craft. The objective of the study was to derive an empirical method for: i) expeditious definition and optimization of hull geometry, and propulsion plant of candidate craft concepts, and ii) assessment of performance claims in boat design proposals and similar technical literature. Parametric relationships were derived to describe the performance characteristics of high speed craft in terms related to lifting surface theory (i.e aspect ratio and pressure loading of the planing surface) rather than in more conventional "naval architectural" terms such as hull geometry coefficients, slenderness ratio etc. The data provide a fast and convenient method for estimation of propulsion power/speed relationships which requires only limited craft design information and yields results consistent with the precision necessary for the intended usage. The scope of the paper includes a brief review of the technical approach used to accomplish the work, typical data trends and the charts which provide the basis for the simplified power estimation method. Performance estimates derived by means of the method are compared with data derived from the careful and thorough testing of full-scale craft.