Precision of the sounding line measurements is estimated at + 0.20 

 foot over water and ± 0.15 foot over land. The soundings were taken over 

 a 1-hour period, centered on the low tide time as predicted in tide tables. 

 Minor irregularities of the profiles (Figures 4, 5) are obscured by the 

 relatively large interval (25 feet) between stations. 



Camp Pendleton Transect 



A profile line was established parallel to and one foot north of the 

 north property line of Camp Pendleton (Figure 1), as follows. Fifteen 

 2-inch steel pipes were jetted into the bottom at 25-foot intervals for a 

 distance of 375 feet seaward of the end pile in a line of pre-existing 

 steel fence posts and wooden piles that marked the property line. The tops 

 of the pipes were then leveled relative to U.S. Coast and Geodetic Survey bench 

 mark datum, as were reference stations along the fence and the pre-existing 

 piles. 



Stations along the offshore portion of the profile line were occupied 

 by swimming from pipe to pipe. A swimmer held a calibrated pole in what 

 he believed to be a vertical position, read the pole at the pipe top, and 

 recorded the value on a plastic disk secured to his neck by a cord. This 

 procedure was followed during the period 10 June - 5 July 1963. Surveys 

 along this line during March and April were made from a DUKW. The accuracy 

 of the determinations was of the order of ± 0.2 foot offshore and + 0.05 

 foot over land. 



Soundings Off Camp Pendleton 



In addition to the profiles to be presented for the Camp Pendleton 

 property line, topographic maps of the nearshore bottom in the area 

 (Figure 1) off Camp Pendleton over the period from May 1961 to April 1963 

 are also presented. 



The field method consisted either of fathometer surveys from rubber 

 boats or handline soundings by swimmers. The swimmers were spaced at 75- 

 foot intervals along a taut line that was moved along perpendicular to 

 shore. At intervals of 75 feet in the direction parallel to shore, each 

 man took a sounding with a calibrated line. (The still water level was 

 estimated) . 



Soundings were reduced to MLW datum and plotted on a map. Values 

 upon which the contoured maps of this study are based are believed accurate 

 to between +0.5 and +1.0 foot. 



