nozzles oriented into the longshore current. Horizontal bars along the bottom 

 of three sides of the rack could be stepped on to bury the 38-cm-long legs. 

 At complete burial, the horizontal bars prevented further penetration of the 

 legs into the bed and kept the lower -most streamer nozzle at the bed. During 

 the course of a deployment (typically of 5- to 10-min duration), the trap 

 operator would periodically step on the horizontal bars to keep the legs fully 

 buried and to counter wave and current action, which would tend to tilt the 

 trap shoreward and downstream, respectively. In weak longshore currents, the 

 streamers would wrap around the vertical bars of the rack with passage of 

 waves, requiring the trap operator to untangle them. In moderate to strong 

 currents (greater than approximately 20 cm/sec), the streamers would fully 

 extend in the flow and require little attention from the trap operator. In 

 fact, during measurement of the sand transport rate in the strong offshore - 

 directed current in the throat of a rip current, the streamers extended fully 

 seaward, against the incident waves, without tangling on the rack or reversing 

 direction. Figure 9 shows the traps being deployed. 



26. At the end of the sampling period, a signal was given from the 

 beach and the traps were pulled from the bed, lifted above the water, and 

 brought to shore (Figure 10). Collected sand was washed from the streamers 

 with seawater onto small patches of filter cloth. The sand sample and cloth 

 (of known weight when wet) were weighed in the drip-free condition (Kraus and 

 Nakashima 1986). Samples from one run per day (all traps) were retained for 

 drying and grain size analysis in the laboratory. The dry weights obtained 

 allowed calibration of the drip-free to dry weight conversion factor. 



27. In between experiment runs and in the evening at the end of each 

 experiment day, the trapped sand weights were inspected and plotted to under- 

 stand qualitative aspects of the transport conditions and to design the next 

 series of runs, such as placement of traps. For example, at first it was 

 thought that there would be enhanced transport in the vicinity of the bar and 

 trough near the step, and it was initially planned to place traps at closer 

 intervals in this area. Since this proved not to be the case by inspection of 

 the trapped sand weights, a more uniform cross-shore placement of traps was 

 implemented. The capability to analyze the transport rate data on site is 

 considered one of the important advantages of using traps, enabling a quality 



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