OBSERVATIONS AND DATA 



Procedure 



On the eighth cruise of USS MARYSVILLE with the therm- 

 istor chain, the ship followed a course about 60-80 miles off 

 San Diego south to near Cape San Lucas, Baja California. The 

 vessel traced a fan-like pattern that extended 100 miles from the 

 Cape and terminated in deep water off Mazatlan (fig. 3). The 

 return trip traced a similar, more widely spaced pattern extend- 

 ing out 170 miles. Advancing at a speed of approximately 6 knots, 

 the chain recorded temperature from the surface to a maximum 

 depth of 750-800 feet. 



Before an analysis of the isotherm recordings derived from 

 Cruise 8 is presented, certain features of sea temperature struc- 

 ture should be described. 



Figure 3. The pattern of thermistor-chain towing on Cruise 

 identification of thermal structure data sections. 



