Durability of reinforced concrete in a marine environment can be impaired as a result of corrosion of the reinforcing steel, chemical attack on the concrete, and alkali-aggregate reactivity. In Australia, steel corrosion is considered to be the main cause of deterioration of reinforced concrete exposed to marine conditions. This Recommended Practice provides designers and specifiers with guidance on the specification of the quality of concrete cover to minimise corrosion of steel through: A review of the different methods that have been used in Australia to specify 'durability' for concrete structures in marine environments; Putting forward recommendations on the 'most suitable' approach currently available to specify durable reinforced concrete in marine environments, and: Recognising that the specification of concrete for marine environments is a developing science, providing information on a selected number of performance criteria currently under development. Performance criteria have been reviewed with respect to their impact on the whole of the design and construction process, these being the design stage, the supply stage (pre-qualification) and the construction state (as quality control tools). Performance criteria have also been reviewed in relation to service life models currently applied to marine structures. Conclusions are drawn from the extensive work carried out by the committee on this subject and the reader is provided with recommendations on appropriate ways in which such performance criteria can be applied on projects.