stopped operations. Emphasis shall be placed on simplicity and 

 rapidity of data collection. 



Requirements and Specifications: 



a. For use on oceanogr aphic survey ships with ship stopped 

 ("lying-to") . It may also be utilized in multiple drops, all posi- 

 tioned and later retrieved by one underway vessel, within a given 

 area. 



b. To be designed as a "free" descent/ascent deep-diving 

 instrument, capable of performing reliably to depths of 6, 500 

 fathoms. 



c. The instrument should be designed to sink to any pre-pro- 

 grammed depth, at a uniform rate compatible with the time res- 

 ponse of attached sensors, recording certain key data during the 

 descent. Upon reaching the pre- specified depth, a mechanismi or 

 weight would be released allowing the instrument to rise uniformly 

 to the surface, recording the data during the ascent. It would then 

 be retrieved by maneuvering the ship and hoisting it on board. 



d. The vehicle shall be so designed that it is compact, light 

 weight, and easy to handle on board ship and in the water. It 

 shall incorporate a provision to aid in the vehicle's location upon 

 surfacing, day or night. 



e. The following modular data sensors shall be included: (1) 

 temperature, (2) salinity, (3) sound velocity, (4) oxygen, (5) depth. 



f. The sensor ranges and accuracies desired are: 



Sensor 



(i) Temperature 



(2) Salinity (two inter- 

 changeable modules) 



(3) Sound velocity 



o o 



Range: -2 to 35 C 



Accuracy : ±0.02°C. 

 Range: to 25%o 



25 to 45%o 

 Accuracy : ±0.01%o 

 ±0.01%o 

 Range: 4, 500 to 5, 500 feet per 



sec ond 

 Accuracy: ±1.0 foot per second 

 absolute at readout 



375 



