Floating wave gauge 

 Electric wave staff 



Fixed wave gauge 



Resistance wire wave 

 staff (Research by U. S. Navy 

 Hydrographic Office; Develop- 

 ment by Atlantic Research 

 Corporation under contract to 

 HO) 



Inverted echo sounder 

 (Edo Corp.— utilized 

 on submarines) 



LIGHT 



Depth: to ZO ft. 

 Accuracy: ±0.5 ft. 



Depth: to 1 5 f t 

 Accuracy: ±0.Z ft. 



Depth: 55 to 100 ft. 



relative to keel depth. 

 Accuracy; ±0.5 ft. 



Pyrheliometer -- soiar 

 intensity (Eppley 

 Laboratory) 



Intensity range: 0.25 to 

 1. 50 g. -cal. /cm.2/min. 



Accpuracy: ± 1 . 5%. 



Wave length range: 3,000 

 to 50, 000 A. 



Radiometer -- long wave 

 and solar radiation; 

 diurnal and nocturnal 

 (Geir and Dunkle) 



Submarine photometer 



Unknown. 



Depth: Approximiately 

 500 ft. 



Hydrophotonneter , Mark 2 



Secchi disc 



Water clarity meter 



(Visibility Laboratory, 

 University of California) 



Depth: 200 ft. 



Depth: 20 ft. (maximum) 



Depth: 500 ft. 



BIOLOGICAL 



Meter or half-meter plankton 

 samplers 



Towing speed: not greater 

 than 2. knots. 



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