PART III: WAVES 



27. This section presents summaries of the wave data. A discussion of 

 individual major storms is given in Part IX and contains additional wave data 

 for times when wave heights exceeded 2 m at the seaward end of the FRF pier. 

 Appendixes B through E provide more extensive data summaries for each gage, 

 including height and period distributions, wave direction distributions, 

 persistence tables, and spectra during storms. 



28. Wave directions (similar to wind directions) at the FRF are 

 seasonally distributed. Waves approach most frequently from north of the pier 

 in the fall and winter and south of the pier in the summer, with the exception 

 of storm waves which approach twice as frequently from north of the pier. 

 Annually, waves are approximately evenly distributed between north and south 

 (resultant wave direction being almost shore-normal). 



Measurement Instruments 



29. The wave gages included one buoy (Gage 630), one pressure (Gage 

 141) and two wave staff gages (Gages 625 and 645), as shown in Figure 2 and 

 located as follows: 



Distance Offshore Water Depth Operational 



Gage Type/Number from Baseline m Period 



Accelerometer buoy (630) 6 km 18 11/78-12/87 



Pressure gage (141) 1 km 9 09/86-12/87 



Continuous wire (625) 579 m 8 11/78-12/87 



Continuous wire (645) 238 m 3.5 11/84-12/87 



Staff gages 



30. Two Baylor Company (Houston, TX) parallel cable inductance wave 

 gages (Gage 645 at sta 7+80 and Gage 625 at sta 19+00 (Figure 2)) were mounted 

 on the FRF pier. Rugged and reliable, these gages require little maintenance 

 except to keep tension on the cables and to remove any material which may 

 cause an electrical short between them. They were calibrated prior to instal- 

 lation by creating an electrical short between the two cables at known dis- 

 tances along the cable and recording the voltage output. Electronic signal 

 conditioning amplifiers are used to ensure that the output signals from the 

 gages are within a 0- to 5-V range. Manufacturer-stated gage accuracy is 

 about 1.0 percent, with a 0.1 percent full-scale resolution; full scale is 



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