Planning Boat Hull Roughness and Influence on Performance, Fleet Economics and Environmental Impact

Biofouling significantly impacts the hydrodynamic performance of marine vessels, leading to increased fuel consumption and operational costs. This effect is pronounced in planing craft, which rely not only on displacement for buoyancy but also on dynamic lift generated by speed, thereby exacerbating fuel consumption on a per unit size basis. Preliminary investigations into the application of existing biofouling drag models to planing craft suggest a marked decrease in transport efficiency, a problem that compounds when managing a fleet of such vessels. With the International Maritime Organization (IMO) setting ambitious targets for reducing greenhouse gas (GHG) emissions from commercial shipping to net zero climate neutrality by around 2050, the contribution of smaller, unregulated planing vessels to overall emissions cannot be overlooked. This paper expands upon previous work by improving the biofilm time-dependent drag model, identifying critical areas requiring further research, and applying these findings to develop a maintenance schedule aimed at reducing operational expenses for a fleet of planing vessels. Through the modified Savitsky method, incorporating roughness effects on lift and drag as developed by Daidola and embodied in the open-source software "OpenPlaning" by Castro-Feliciano, this research presents a life cycle impact analysis of hull roughness on fleet operations. The study explores mitigation strategies for hull roughness, including cleaning frequency, bottom treatments, and coating applications, their effects on vessel speed, fuel consumption, and GHG emissions. By integrating these strategies into the planing boat hydrodynamic evaluation tool, this paper advances the framework for predicting and improving life cycle vessel performance.