TM No. 327 



Both vessels vere equipped -with Decca navigation radar and standard ship- 

 to-shore transceivers. Decca Hi -Fix receivers were installed on each vessel 

 and used in combination with the radars to track the drogues. Thus^ if one 

 system failed, tracking could be continued with the other system alone. 



With two vessels tracking their respective drogues simultaneously at 

 various distances from each other , it was; possible to make synoptic current 

 measiirements (using drogues) for the first time in the area.. In addition, 

 the program was not interrupted when one vessel had to return to port. 

 This was important, since quasi- continuous measurements were desirable in 

 order to determine meaningful flow patterns. 



CLIRRENT MEASllREMEDMT AREAS 



Five areas were selected in the Northeast Providence Channel and the 

 Tongue of the Ocean, and water current measurements were taken along transects 

 in these areas (figure l). 



The first transect (Tl) was between Northern Eleuthera (Egg Island) and 

 Great Abaco Island ( Hole -in-the -Wall), This transect was selected to define 

 water motion at the entrance to the Northeast Providence Channel, 



The second transect (T2) was along a line bearing 3k3°T from Old. Fort 

 Point (New Providence Island) and terminating east of the Berry Islands at 

 the 100 fathom curve. 



The third transect (T3) extended eastward from the longitudinal axis of 

 the Tongue of the Ocean (broken line in figure l) to the east bank along 

 latitude 2k° UO'N. 



The fourth transect (T'+) was parallel to the west bank of the Tongue 

 about three miles east of Middle Bight on Andros Island, The drogues set 

 along Th were tracked simultaneously with those set along T3, 



The fifth transect (T5) extended westward from the longitudinal axis 

 of the Tongue to the west bank along latitude 24° 15 'N. Drogues set along 

 T5 were also tracked simultaneously with the drogues set along T3 (after 

 tracking was completed along Tk), 



A total of 27 drogues were set and tracked along these five transects, 

 and 19 of the surface floats were recovered. The drogues were placed at 

 predetermined depths to provide Information on the character and velocity 

 of the water currents throughout the water column. Table 1 shows the 

 number of drogues tracked along each transect, the depth at which each 

 drogue was set, and the total tracking time per drogue. 



