There are several ways to protect the rod person during cold-water surveying. 

 The most effective protection (also the most expensive) is a skin diver's dry 

 suit worn over clothing; however, in hot weather the suit becomes too warm. A 

 wet suit may be substituted, but it also becomes uncomfortable during a full day 

 of surveying. A pair of waders worn under a flotation jacket (Fig. 2) provides 

 adequate comfort and emergency buoyancy. High surf conditions should be avoided 

 and a safety line kept handy for emergencies. 



Figure 2. Rod person wearing waders and flotation jacket. 



Ill . MONUMENTATION 



Since survey distances are measured relative to the location of the instru- 

 ment, its position on the profile line must be accurately determined. Each 

 profile line should be located by a permanent survey monument made from a con- 

 crete cylinder of deep-driven steel pipe. The elevation of this monument should 

 be established since it will serve as the bench mark (BM) for each survey of the 

 profile line. The monument also serves as the start of the profile line with 

 all distances measured from it . 



To accurately determine the instrument location, the distance from the in- 

 strument to the survey monument should be tape measured. This is not always 

 practical if the monument is located a distance from the beach. Since this is 

 often the case, some additional monumentation along each line to be surveyed 

 (assuming repetitive surveys are planned) is required. Figure 3 shows a typi- 

 cal profile line (see Hemsley, in preparation, 1981, for details on establishing 

 primary monuments)'*. A 3-foot (1 meter) wood or pipe temporary bench mark (TBM) 

 is set online and near the best possible instrument location (in a stable part 

 of the profile near the beach) . The elevation and location of the TBM are 

 accurately determined from the profile monument. The distance from the profile 

 monument to the TBM should be taped. 



^HEMSLEY, M.J., "Guidelines for Establishing Coastal Survey Base Lines," U.S. 

 Army, Corps of Engineers, Coastal Engineering Research Center, Fort Belvoir, 

 Va. (in preparation, 1981). 



