Relationships have been developed from laboratory experiments which show the effect of side slope, wave steepness (H/L), relative depth (d/L), and the structure porosity on wave run‐up. Maximum wave run‐up occurs, for the range of angles examined, at approximately 30°. As the wave steepness (H/L) increases, the wave run‐up increases, and as the relative depth parameter (d/L) decreases, the wave run‐up increases. The wave approach was restricted to the direction perpendicular to the axis of the structure.