Another serious instrumentation problem in acoustics is the 

 determination of the acoustical properties of the ocean bottom 

 from a ship underway. There is a foreseeable need for a blackbox 

 which can be attached to a common echo sounder and which will 

 give us even a rough indication of the type of bottom (physically 

 and acoustically speaking), the special characteristics of acoustic 

 absorption and reflection over a broad band of frequencies. 



Turning now to ocean WAVE MEASUREMENTS discussed by 

 Mr. John Schule, Jr . , I will just remind you that the Bureau 

 builds ships and submarines. In most ships the structural 

 stresses, the seakeeping qualities, and the combinations of the 

 ship's inertia and the processes of energy transfer, all, involve a 

 somewhat limited wave spectrum compared to the overall fre- 

 quency spectrum of the sea. Surface wave information and inter- 

 nal wave information from the region of the thermocline would be 

 of interest. Far outside the spectrunn of interest in ordinary ship 

 design, the high frequency spectrum affecting sea clutter is 

 important. Right now we do not really know fully how a wave is 

 born and grows in the sea as a measured sequence of events. 

 It is probable that a whole series of "wave meters" will be re- 

 quired in the future. Considerable attention to a better descrip- 

 tion of sea state for use by engineers is a recognized problem on 

 which professional societies (such as the Society of Naval Archi- 

 tects and Marine Engineers) are now working. 



As to ANTIFOULING AND CORROSION EFFECTS, a great 

 deal has been learned from the studies of antifouling paints and 

 the moth-balling of ships. However, the deep waters of the ocean 

 are practically unexplored in this respect. Yet the commercial 

 cables and deep anchoring systems show evidence of considerable 

 activity at all depths. Improved pH meters, conductivity meters, 

 techniques for rate-of-growth measurennent, and techniques for 

 the study of fouling organisms as they apply to particular mater- 

 ials are all fruitful fields. The connprehensive report, "Marine 

 Fouling and Its Prevention, " prepared for the Bureau of Ships 

 by the Woods Hole Oceanographic Institution, and printed by the 

 U. S. Naval Institute in 1952, has now been pretty well digested 

 and we should be moving on. 



DEEP OCEAN CURRENT VELOCITIES are extremely impor- 

 tant in deep-water navigation and to deep-ocean structures. 



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