Reef Breakwaters for Coastal Protection: A State of the Art Review

Reef breakwaters are widely employed soft engineering solutions to control shoreline erosion and to protect the existing coastal structures from increased wave action. The adoption of reef breakwaters for coastal protection has been growing owing to several benefits, such as protecting the coast by reducing wave energy, enhancing the performance of existing coastal structures, and fostering recreational activities such as surfing and aquaculture. This article is aimed at presenting a comprehensive review of the application of reef breakwaters intended for coastal protection. The review comprises the state-of-the-art development in the utilization of reef breakwaters for coastal defense; exploring their hydrodynamic performance characteristics, such as wave transmission and reflection based on previous studies. The work also consists of a review of the stability features of reef breakwaters and their potential application as engineering solutions for coastal protection and as retrofits to existing coastal structures. The ancillary benefits of reef breakwaters applied for surfing and aquaculture are explored and brought out in this work. Despite the existing body of research on the efficacy of reef breakwaters for coastal protection, this paper brings out the research challenges and outlines potential directions for future studies.