26 



Figure 33. 



-Tracks of drogues placed In a large 

 eddy near Oahu. 



tank where ocean surface currents can be simulated by flowing 

 a mixture of fresh water and sea water over a heavier layer 

 of sea water which fills the tank to within an inch or less of 

 sea level on the model. The currents then can be marked 

 with dye and photographed for later analysis. Preliminary 

 results from the model show eddies and other features of the 

 near-surface currents agreeing well with field observations. 

 The model has the important advantage of making it possible 

 to study events that take place simultaneously over large 

 areas, instead of point by point, as in field work. At the same 

 time, conditions such as current speed, angle between the 

 current and the island chain, and depth to which the near- 

 surface current extends can be varied in the model, with the 

 result that events requiring weeks to develop in nature occur 

 within minutes in the scale model. 



