located 610 m offshore of the original shoreline. This shore-parallel struc- 

 ture is situated at a mean water depth of -8.4 m MSL and has a crest at +2.2 m 

 MSL. The mean tide range is 1.1 m. Although the breakwater's original pur- 

 pose was to provide a harbor of refuge for small craft, the shoreline response 

 demonstrates the application of detached breakwaters for shore protection. It 

 was completed in 1934, and by 1948 the shoreline behind the structure had 

 accreted 240 m, while the downdrift shoreline experienced substantial erosion. 

 The region shoreward of the structure was subsequently dredged and the mate- 

 rial placed on the downdrift beach. The structure has lost crest elevation 

 allowing some wave transmission (Figure 8b) . The salient has never developed 

 into a tombolo. 



Haleiwa Beach, Hawaii 



19. The Haleiwa Beach breakwater (Figure 9) was constructed in 1965 and 

 protects a park facility and war memorial monument. It is a single imperme- 

 able, rubble-mound structure, 50 m long and approximately 90 m offshore of the 

 original, eroding shore. Water depth at the structure is 2.1 m MSL, crest is 



Figure 9. Breakwater at Haleiwa Beach, Hawaii (1966) 



19 



