17 



ing of cables several miles long may be considerable, and even if a float were 

 initially below the surface, elastic extension and subsequent slow creep might 

 allow it to reach the surface with effectively no scope. Either surfaced or sub- 

 merged, buoys must be designed to withstand considerable hydrostatic pressure 

 since they are liable to be towed under when they happen to lie in the paths of 

 strong currents. It seems likely that buoys might be towed under to depths as 

 great as 55 meters in the Gulf Stream, so that they must be designed to survive 

 exposure to more than the pressure at this depth, even though they are to be pri- 

 marily surface or near-surface floats. 



There are advantages in placing buoys in the region of strong wave action 

 since they may be recovered more easily and in this position they might provide 

 information on the intensity of wave action or use it as a source of power. For 

 example, a pendulum arranged to wind a spring could drive a generator as a 

 trickle charger for storage batteries. It is interesting to note that storage bat- 

 teries preclude the use of sealed floats due to the hydrogen they generate. A 

 check valve of some kind will be required to prevent explosions. 



Finally, there are the problems of telemetering or recording the data 

 obtained at the stations aAd servicing the buoys. If the surface buoys are lo- 

 cated far enough apart, the time of sunrise and sunset will schedule transmis- 

 sions mainly according to longitude. Should a buoy break loose this fact will be 

 known by the unusual transmissions schedule and the inconsistent nature of the 

 data transmitted. If the buoy is not heard from for a few days it may have been 

 towed under temporarily, but if it is not heard from for some longer time, it 

 must be either sunk or in need of repair. Under these circumstances a service 

 vessel is to be dispatched. 



The service vessel will be faced with a difficult problem in navigation; 

 to find an object nearly awash and possibly no more than 5 or 10 feet in diameter 

 at anchor in 2 or 3 miles of water on a scope of perhaps 1 .5 to 1 . Sonar may 

 help, but a radio homing transponder might shorten an otherwise lengthy search 

 if the buoy has sunk. Since a service vessel may be needed quite often, it will 

 have opportunities to contribute numbers of observations gathered en route. 



Protest might be raised against ocean buoys as a menace to navigation. 

 As a safety measure the buoys, though able to withstand fairly high hydrostatic 

 pressure, should be brittle and break apart on impact. Glass and some plas- 

 tics have this combination of properties. Similarly, the cable anchoring them 

 to the bottom should be strong in tension but weak in shear, as are glass and 

 some plastic fibers, so that the diving planes and screws of submarines may not 

 be fouled. Plans have been considered in which a submerged float, to lift the 

 burden of the cable's weight, lies below wave action, while a smaller float on 

 the surface may house a radio transmitter and support the antenna. Buoys for 

 this arrangement might be made to resist impact since the smaller float would 

 have little inertia and its cable be small, while the deeper float and stronger 

 cable might be placed below the range of submarine navigation. 



From a more positive point of view, an extensive grid of anchored buoys, 

 if listed on charts, might serve as position markers in the otherwise trackless 

 ocean. If buoys were to be equipped with a suitable button marked "DISTRESS 

 CALL" they might be activated to that purpose and serve as a mooring for life- 

 boats until help arrived. Such a service built into ocean buoys might cause 

 them to be respected by mariners. 



There has been some thought given to the choice of recording or tele- 

 metering data from ocean stations. It seems best that both be done. A tele- 



