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Marine corrosion is one of those generic titles that many understand but very few can define. Basically it is corrosion due to sea‐water but, in fact, the worse corrosion is experienced when the sea‐water is present in the form of a mist. Any consideration of marine corrosion must, in consequence, be based on the corrosivity of sea‐water, sea‐water‐laden atmospheres, and mixtures of these.

In this special feature details are given of those British paints which can be described as corrosion‐resistant primers, both one‐ and two‐pack. The materials are generally classified according to the base or pigment which actively prevents corrosion—e.g. metallic zinc in zinc/epoxy formulations— or by the base which produces a barrier action against corrosion, e.g. bitumen in bituminous paints. Exceptions to this are the etching primers, which are separately classified. About 300 primers are described, the manufacturers' names and addresses being cross‐indexed and listed separately on page 48.

The paper aims to focus on the recognition of corrosion product morphologies of AA5083‐H321 corroding aluminum‐magnesium alloys used in the manufacture of aluminum high speed boats and submarines during flow induced corrosion in seawater.

All experiments were conducted in a 3.5 percent NaCl solution as the simulated marine environment. Hydrodynamic conditions were created by an rotating cylinder electrode (RCE) system. Morphological characterization of the surface was undertaken using SEM and EDAX techniques. Cyclic polarization tests were used to determine the electrochemical behavior of the alloy.

The results obtained reveal that the pit density on the sample surface increased with increasing the rotation speed. The enhanced flow condition also enhanced the tendency for intermetallic particles, including submicron size Al(Mg,Mn) inclusions, to promote pitting corrosion of the alloy. An interesting result was that crystallographic pitting occurred at rotation speeds greater than 5 m/s.

In the selection of corrosion control methods for high speed aluminum‐hulled boats, control of erosion corrosion was determined to be more important than any other form of corrosion.

Provides information about the contribution of mechanical and electrochemical corrosion phenomena in corrosion of high speed aluminum boats under hydrodynamic conditions. Characterization of new intermetallic particles in aluminum‐magnesium alloys that can promote pitting during flow induced corrosion in marine environments. Provides new information about the origin of crystallographic pitting attack on aluminum.

Pure metal lead in a very finely divided form has quite different electrochemical properties from lead in the massive state and is a paint pigment of exceptional rust‐inhibitive power. ‘Genuine’ metallic lead paints have been known for nearly 30 years, but only in the last decade has extensive practical use of ‘extended’ paints, in diverse environments, shown them to provide protection at least equal to that given by red lead.

For many years sprayed metal coatings have been generally regarded as being undercoats for paint systems on iron and steel surfaces, thin coatings of zinc, aluminium or zinc aluminium alloy being applied to increase the adhesion of the paint and to prevent corrosion at the paint/base metal interface. This mode of practice was probably logical when the paint formulations changed to the use of the more resistant resins such as epoxides and before the need for adequate surface preparation was accepted. Sprayed metal coatings have always needed adequate surface preparation as an integral part of their application, so that understandably the good performance in service of such thin metal coatings followed by the application of these resistant paints encouraged the use of cognate coatings, as they represented a measure of insurance against premature failure.

The purpose of this study is twofold: first, to derive a consistent model free-surface runup flow problems over deformable beds. The authors couple the nonlinear one-dimensional shallow water equations, including friction terms for the water free-surface and the two-dimensional second-order solid elastostatic equations for the bed deformation. Second, to develop a robust hybrid finite element/finite volume method for solving free-surface runup flow problems over deformable beds. The authors combine the finite volume for free-surface flows and the finite element method for bed elasticity.

The authors propose a new model for wave runup by static deformation on seabeds. The model consists of the depth-averaged shallow water system for the water free-surface coupled to the second-order elastostatic formulation for the bed deformation. At the interface between the water flow and the seabed, transfer conditions are implemented. Here, hydrostatic pressure and friction forces are considered for the elastostatic equations, whereas bathymetric forces are accounted for in the shallow water equations. As numerical solvers, the authors propose a well-balanced finite volume method for the flow system and a stabilized finite element method for elastostatics.

The developed coupled depth-averaged shallow water system and second-order solid elastostatic system is well suited for modeling wave runup by deformation on seabeds. The derived coupling conditions at the interface between the water flow and the bed topography resolve well the condition transfer between the two systems. The proposed hybrid finite volume element method is accurate and efficient for this class of models. The novel technique used for wet/dry treatment accurately captures the moving fronts in the computational domain without generating nonphysical oscillations. The presented numerical results demonstrate the high performance of the proposed methods.

Enhancing modeling and computations for wave runup problems is at an early stage in the literature, and it is a new and exciting area of research. To the best of our knowledge, solving wave runup problems by static deformation on seabeds using a hybrid finite volume element method is presented for the first time. The results of this research study, and the research methodologies, will have an important influence on a range of other scientists carrying out research in related fields.

The scientific world has for a long time worked with linear tools to explain complex non‐linear phenomena. Also non‐linear relationships were transformed to linear in order to be handled. This was so despite the fact that nature has been giving us examples showing that the real world was complex, dynamic and non‐linear. This was so until developments in computer science provided the calculating means to the theory of complexity. Today, the theory of complexity is applied to many sciences and to disaster management as well. The application of complexity theory is attempted from a disaster management point of view. As the first attempt to incorporate management science into marine disaster prevention was the so‐called International Safety Management Code of the International Maritime Organization in 1998, we will attempt to connect the theory of complexity to the ISM code. The ISM code, being a safety standard, has been based on good management and organization rulesl. However, ISM code was accused of increasing the bureaucracy of the system with a result that no substance work could be done at the end. Moreover, a need has now emerged, i.e. to establish a “particular ISM code man” among the crewmen on board all ships. On the other hand, modern complexity management suggests more flat hierarchies where information travels faster, and this is something needed in a marine disaster.

Corrosion of steel in marine environments poses a significant economic and environmental challenge because of its detrimental effects on marine structures and equipment. Traditional chemical inhibitors that mitigate corrosion often introduce harmful substances into the environment. As a result, there is a growing interest in exploring eco-friendly alternatives, such as plant-derived inhibitors, to reduce the environmental impact of corrosion protection strategies. The purpose of this study is to investigate the effectiveness of Phyllanthus urinaria extract as a green anti-corrosion additive for rebar steel in marine conditions.

Phyllanthus urinaria extract was prepared in the ethanol solution with the assistance of a sonicator. The steel’s surface upon addition of the extract was characterized using SEM, EDX and FTIR analysis. The electrochemical corrosion characteristics, including potentiodynamic polarization and electrochemical impedance spectroscopy, were used to evaluate the inhibitory performance of the extract on steel under simulated marine conditions (3.5% NaCl solutions).

The results of this study showed that with Phyllanthus urinaria extract’s content of 0.02% in NaCl solution of 3.5%, the corrosion rate decreased to about 30% compared to the controlled sample. Measurements of the inhibitory mechanism analysis study for all solutions from 0 mg/L to 1.114 mg/L of polyphenol from Phyllanthus urinaria extract showed a significant reduction in rebar corrosion rate, especially with 0.2228 mg/L polyphenol. Reinforcement can increase corrosion inhibition by up to 30% compared to the control sample.

To the best of the authors’ knowledge, this is the first study of using Phyllanthus urinaria extract as green inhibitor for protection of steel from the corrosion in the simulated marine solution. The protective mechanism for steel using Phyllanthus urinaria extract was investigated using the FTIR, SEM, EDX and electrochemical analysis. The results indicated that the polyphenols in the extract showed inhibition that could minimize the corrosion of reinforcement in marine environments.

OVER THE PAST FEW YEARS interest has grown in Britain and elsewhere in the use of extreme‐pressure (e.p.) lubricants (or more correctly perhaps, though less conveniently, load‐carrying additive lubricants) for marine main propulsion gearing, and many ships now go to sea with such lubricants in their main systems. Several technical papers on the development of such lubricants have been contributed recently, for example by Elliott and Edwards and Socolofsky and others, the main purpose of this paper is to indicate present and likely future marine main reduction‐gear requirements and to discuss how far these are met by the developments in extreme‐pressure lubricants.

The conditions to which marine paints are subjected are undoubtedly very much more severe than those which any similar types of paint meet on land. Conditions of application, which are more often than not bad, add further complications. In dry‐dock painting the ship must undock to schedule and painting must, therefore, go on regardless of rain, frost and fog. As a result, most marine paints and compositions for the outer hull must be a compromise between the ideal and the practical, rather than the best possible material which could be used under perfectly controlled conditions.