TOWED SUBSURFACE INSTRUMENT SYSTEM 
Sketches 
(To be provided) 
Primary Uses 
This device is designed for utilization on oceanographic survey 
ships for underway operations to obtain horizontal profiles of certain 
key oceanographic variables. It is to be a streamlined, compact 
platform to which will be attached modular sensors and other special 
miniaturized instruments capable of being towed submerged at moderate 
Speeds. 
Requirements and Specifications: 
a. The platform with associated instruments shall be capable of 
being towed from an oceanographic survey ship at any constant depth 
within a depth range of O0-2,000 feet at any ship's speed ranging from 
3 to 15 knots. In addition, a feature should be incorporated in the 
vehicle design to permit continuous, controlled variation of the plat- 
form's depth over the entire operating depth range or any increment 
thereof. 
b. The towing wire angle shall not exceed 25° from the vertical. 
c.- The platform and associated instruments shall be compact, 
streamlined, and not excessively heavy or bulky in order to allow 
rapid and adequate deck stowage and/or to permit smooth entry into or 
hoisting out of the water. 
d. The following sensors shall be included: 
Sensor Range Accuracy 
Temperature =2 to 435°6 +0.01° 
Salinity (two inter- 
changeable modules) 0 to 25°/o0o +0.01°/00 
25 to 45°/o00 +0.01°/o00 
Sound Velocity 4,500 to 5,500 +l foot/sec absolute 
feet/second at readout 
Depth (two inter- O to 600 feet +0.25% of full scale 
changeable modules) O to 2,000 feet 
44 
