to replicate the shoreward region of the south jetty and some of the navigation channel in the
laboratory facility. This work confirmed the design. Figure 8 shows the existing condition in the
model and the plan selected for construction. The wave angle sweeping along the shoreline is
modified by the mound, directing it more perpendicular to the inner bank shoreline. Also wave
heights were significantly reduced in this region. Figure 9 shows the structure as constructed in
Figure 8. Model study photos: left photo shows the pre-diffraction structure condition and right
photo the mound structure diffracting waves.
Figure 9. Mound diffraction structure as constructed at Grays Harbor,
Half Moon Bay.