LEGEND 



a PRIMARY TIDE GAGE 

 ■ REDUNDANT TIDE GAGE 

 ° SURGE GAGE 

 * NOS TIDE GAGE 



Figure 2. Tide gage deployment site map 



9. The flexibility and relative security of this type of gaging are 

 always offset by the potentially lower reliability of data recovery since gage 

 nonperformance is only apparent after removal of the gage. To enhance relia- 

 bility, redundant gages (TG5-TG8) were deployed for each of the four primary 

 gages (TG1-TG4). 



Instruments 



10. Details on all instruments, including manufacturer's specifications 

 are found in Appendix A. The tide gage selected uses a vibrating quartz crys- 

 tal pressure transducer whose output is proportional to absolute pressure. 

 Oscillations of the crystal are counted over some selected sample interval, 

 and this integrated pressure is averaged over that interval to filter wave 

 frequency signals. The average pressure is recorded as a 16-bit digital word 

 on a magnetic tape along with a time word from a quartz clock. Shorter sample 

 intervals retain more information but require more storage on the tape, short- 

 ening deployment time. To obtain the required 3 months of data on one 



