Predicting wave transmission past Reef Ball (TM) submerged breakwaters

Reef BallsTM are hemispherical shaped artificial units, made of neutral concrete and characterized by a particular surface textures to promote the growth of marine life. They can be arranged in different layouts to form submerged breakwaters, even of significant width. Although structures in Reef Balls have been employed for the protection of a number of top quality sites, no well-established design tool exists for the prediction of wave transmission behind them. In this article a set of equations is provided, based on the so-called “Conceptual Approach” originally developed for ordinary structures. The new expressions proved to fit properly more than 300 experimental data, coming from physical model tests conducted at two different American laboratories: Queen’s University Coastal Engineering Research Laboratory (Canada) and the USACE Engineering Research and Development Center Coastal and Hydraulics Laboratory (USA).