Marine biofouling is an increasing problem from both economic and environmental points of view in terms of increased resistance, increased fuel consumption, increased GHG emissions and transportation of harmful non-indigenous species. Marine coatings are prevalently used to mitigate biofouling and smooth the surfaces of hulls. This paper aims at introducing new horizons and novel approaches in marine antifouling coatings. Firstly, marine biofouling and fouling prevention methods are briefly introduced. Afterwards, latest research in coating/fouling hydrodynamics is presented. Biomimetic approach to antifouling technology, bio-inspired antifouling strategies and the challenges in designing bio-inspired antifouling coatings are then discussed in detail. It is believed that, the on-going research in marine coatings will lead to an effective mitigation of marine biofouling while maintaining the harmony between man-made structures and marine life.

This paper reviews two decades of bridging the gap between laboratory measurements and predicting the performance of commercial maritime vessels and presents a rational approach, which is based on the combination of an experimental and a computational procedure, to predict the effects of modernday fouling control systems on “in-service” ship performance. Here the word “rational” reflects ship hull (and propeller) conditions as well as the approach to predicting the effect of the hull coating systems under such conditions. The proposed approach arguably provides a full solution to the complex ship performance problem. It is “rational” in terms of tackling the main features of modernday hull coating systems with the aid of bespoke experimental testing facilities and state-of-the-art computational methods. The proposed approach is generic and can be applied to any ship type and hull coating system in the presence of biofouling and it may even be combined with passive drag reduction systems. This approach involves both the combination of experimental data from flat test panels treated with representative surface finishes and extrapolation of this data to full-scale. However, for more accurate and direct estimation of performance prediction at full-scale, the extrapolation procedure needs to be replaced with Computational Fluid Dynamics (CFD) methods, especially for deteriorated hull surfaces due to fouling; at present, such experimental data are still required. The rational nature and hence strength of the proposed approach is to represent the effect of the actual hull surfaces “in-service” by using state-of-the art experimental methods and data. This provides the option of an extrapolation procedure for practical performance estimations and also enables the use of CFD methods by avoiding the most difficult barrier of describing the actual hull surface numerically in CFD. Validation of the proposed approach requires full-scale data to be collected using a bespoke ship performance monitoring and analysis system which is dedicated to assessing the effect of coating systems in the presence of fouling. Such a system is under development as detailed in an accompanying presentation.

Newcastle University’s (UNEW’s) enhanced the test section of their existing flow-cell facility. New measurement section is to measure the pressure drop (and hence frictional drag) across coated surface of a standard flat test panel (of Length x Width x Thickness: 0.6m x 0.22m x 0.015m in size). The panel can be tested as cleanly coated as well as exposed to light biofilm growth. Based on pressure gradients the calculated skin friction coefficients of these surfaces were compared with the results of the measurements obtained by other well-established methods to predict the skin friction, i.e. measuring boundary layer of the same surfaces using a Laser Doppler Velocimetry (LDV) system in the UNEW’s Emerson Cavitation Tunnel (ECT), to evaluate the pressure drop methodology. This paper presents design and calibration of the flowcell to investigate skin-friction of three different surfaces coatings in a fully developed turbulent flow.

Under a time charter, upon delivery commercial exploitation of a ship is placed in the hands of the charterer in exchange for payment of hire. During the agreed charter period, the charterer can send the ship to anywhere within the geographical limits of the charter. There is, therefore, nothing in principle that prevents the charterer from ordering the ship to proceed to tropical waters unless the charter contains a restriction in this regard. Such an order of the charterer is accepted as legitimate employment order and the shipowner is required to comply with it. If the shipowner refuses this order without any good reason, his conduct may constitute a repudiatory breach, so that entitles the charterer to terminate the charter. The problem is that where the ship remains in tropical waters for a long period, hull fouling mostly arises. This natural event can be defined as an accumulation of marine organism such as barnacles and weeds on the ship’s hull. It may affect performance of the ship and cause that the ship proceeds at less speed and consumes more fuel than the specified in the charter. In such a case, if the charter contains an undertaking by the shipowner that the ship proceeds at particular speed and consumes particular amount of bunker on that speed during the period of charter, it is likely the shipowner exposes the charterer’s claim for underperformance of the ship. Following these explanations, it is clear that the charterer’s order concerning the employment of the ship in tropical waters for a prolonged period is not a kind of order which the shipowner can follow without any concern. Upon the charterer’s this order, the shipowner usually confront a dilemma. On the one hand, there is an order which the law requires him to comply with it, but on the other hand his continuous undertaking as to the ship’s speed and bunker consumption under the charter. The purpose of this paper is to evaluate the limits of the shipowner’s liability for underperformance caused by hull fouling that arises as a result of complying with the charterer’s employment order. The paper also aims to analyse to what extent incorporation of BIMCO Hull Fouling Clause for Time Charterparties into the charter reduces underperformance disputes arising from hull fouling.