Breakwaters are structures built to dissipate wave energy in order to provide tranquil water at the port entrance. The term living breakwaters is used when such structures have been deliberately constructed to provide a habitat for species or to aid the restoration of coastal reef ecosystems and support the services that they provide. Artificial structures that aim to mimic some of the characteristics of natural reefs, including their function as breakwaters, are sometimes referred to as artificial reefs. Living breakwaters/artificial reefs come in various sorts and shapes ranging from purpose-built concrete structures to objects previously used for other purposes (e.g. old ships and gas platforms). They can also be used for various other purposes other than providing tranquil navigation waters like ecosystem restoration to hard infrastructure development. Therefore, approaches to living breakwaters/artificial reefs vary depending on their main purpose.