strength for approaching vessels. Four people were aboard on each shift: a 

 boat operator, a forward deck hand, a stern deck hand/meter handler, and a 

 data recorder. Again because of the high traffic volume, safety dictated the 

 need for at least two people (the operator and a deck hand) to have no other 

 duties than the safe maneuvering of the boat, maintaining a lookout at all 

 times, and being prepared to slip a mooring and be underway without hesita- 

 tion- -and without distraction by the profiling duties- -if a ship approached 

 too closely. 



37. Every profile experiment started with the placement of temporary 

 lighted mooring buoys at each station site. The buoys permitted each station 

 to be rapidly and precisely recovered by the boat, which could use the buoy 

 together with a bow anchor in a two-way mooring. This system was chosen to 

 prevent the wind- induced "sailing" from side to side experienced by a boat 

 moored only at the bow. Any boat motion would seriously affect the accuracy 

 of the current data, particularly in the low- velocity regime of the harbor. 

 Thus, a station was recovered by dropping the bow anchor upwind/current of the 

 buoy and backing down until the stern deck hand could secure to the buoy. 



38. At stations located in the center of a narrow shipping channel, 

 even a temporary buoy would be an unacceptable hazard to traffic. In those 

 cases, a stern clump anchor, lowered after the bow anchor had paid out suffi- 

 cient scope, served the same purpose as the buoy. 



39. Once the boat was secured on station, the meter was lowered to the 

 bottom. The water depth was obtained from the meter's pressure transducer and 

 compared with the graduated marks on the meter cable and to the boat's sounder 

 to ensure accuracy. The meter was then raised to 90 percent of water column 

 depth and allowed to stabilize, and the velocity and direction together with 

 the time and depth of the reading were recorded from the surface display. 

 After repeating the measurement at 50- and 10-percent depths, the meter was 

 pulled aboard and the anchor (s) retrieved. For a range with five stations, 

 each profiled at hourly intervals, the allotted time for that procedure was 



12 min. To avoid data gaps at shift changes, a separate shuttle boat was used 

 to transport crews between the measuring boat and shore. 



18 



