could complete the survey of a beach profile line in less than 5 minutes. 

 The survey of all four nearshore profile lines at Boca Raton was gener- 

 ally accomplished by a team of two divers in 30 to 45 minutes. The sand 

 level measuring techniques are such that a minimum of training is required 

 to complete a survey. The method has been used quite successfully, on a 

 limited scale, at several other localities using unpaid observers with 

 no previous surveying experience (Urban and Galvin, 1969). 



Disadvantages of the pipe profile method include a smoothing effect 

 on the surveyed profile shape, the problem of lost or damaged pipes, the 

 possibility of misidentified pipes, and the difficulty of removing the 

 pipes when the study is completed. Standard tape and level techniques, 

 if properly done, will pick up major changes in slope as they occur be- 

 tween the standard-interval stations (Fig. 19). Normally, breaks in 

 slope between pipe stations were not recorded in this study, except for 

 the positions of the berm crest and any major scarps. The overall effect 

 is one of smoothing the profile shape, which may or may not have a signif- 

 icant effect on the variable being analyzed. A continual problem with 

 the pipe surveying method is the damage or loss of pipes, either through 

 natural causes or vandalism. Damaged or lost pipes were replaced as 

 required and new pipes were referenced horizontally and vertically with 

 respect to adjacent pipes. Those pipes below MSL were occasionally 

 buried by migrating bars. Burial lasted from 1 day to several months. 

 If extended burial was apparent, a new pipe was installed and releveled 

 from the bench mark. The effect of buried pipes was an artificial trunca- 

 tion of bed forms on the plotted profile, which might alternately reappear 

 as pipes were excavated or replaced (Fig. 38). Similarly, buried pipes re- 

 sulted in large artificial gains and losses being computed for the volume 

 changes. This problem was particularly evident for the nearshore surveys 

 at Boca Raton completed during the last 4 or 5 months of the study. 



A problem not fully recognized at the outset of the study related to 

 the safety aspects of the pipe profiling method. Initially, precautions 

 were taken to ensure that the pipes were clearly marked with warning 

 signs, fluorescent paint, and flagging. Later, broken pipe stubs, which 

 were often rapidly covered with sand after storms, posed a hazard not 

 only to unwary bathers, but also to the observers. When the stubs could 

 be located, they were cut off smoothly and rethreaded so a new pipe sec- 

 tion could be coupled to the top. This was not always easily accomplished, 

 as in the breaker zone where visibility was restricted, the stubs quickly 

 covered, and working conditions the most difficult. 



At the end of the data collection phase of the study another unantici- 

 pated problem was encountered in removing the pipes. Previous studies, 

 where jetted-in pipes were removed seasonally, encountered little problem 

 in clearing profiles (Urban and Galvin, 1969). However, in this study 

 many of the pipes had been in place for nearly 5 years and had been driven 

 into beach rock. Complete clearing required the use of jetting gear, heavy 

 equipment (a borrowed bulldozer), and, in some cases, explosives. Examina- 

 tion of the pipes after removal showed that many pipes had been severely 

 deformed below the sand surface either during installation or during 



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