Page 165 control and signal building 2814 



is made to be used in a standard four-prong radio tube socket and it should be mounted under a 

 standard watertight launch masthead fixture. An "Eveready Luminous Tube Operating Unit," 

 manufactured by the National Carbon Company has been found a very satisfactory flasher unit 

 This type of flasher unit is made in three different models, classified according to the flashing frequency. 

 These are for 80, 200, or 400 flashes per minute which will operate for 110, 100, or 40 days, respectively, 

 when supplied with current from a 6-volt hot-shot battery. The flasher unit is permanently sealed 

 and it must be mounted in an upright position for the switch to operate efficiently. The Amglo 

 Corporation also manufactures a flasher unit called "Flasherpak." The flasher unit and battery 

 maj' be contained in a watertight box whose inside dimensions are 6 by 8 by 18 inches. Exterior 

 connections must be made with waterproof cable, such as "Tyrex." 



2814. Buoy Identifying Marks 



For identification during field operations, the name of the station is painted on 

 the superstructure of each survey buoy or on a piece of signal cloth tacked thereon. 

 In addition, ordinary survey buoys (not sono-radio buoys) may be identified by flags 

 of various colors used in various combinations attached to a short staft" at the top of 

 the buoy superstructure. Sufficient combinations of three colors are possible so that 

 no two buoys in a locality will have the same combination. 



Identifying flags on survey buoys are of particular value in starting a sounding 

 line. The stations may be identified from a distance so that it is not necessary to 

 maneuver close to them in order to read the names. The flags also aid in identifying 

 a drifting buoy seen during survey operations. 



A sono-radio buoy is marked with the name of the R.A.R. station but flags should 

 not be used. Each should be marked with a sign, however, warning vessels to keep 

 clear. These signs are made of baked enamel on a metal base and are designed to 

 fit on the wooden buoy structure. They contain a legend, "Survey Buoy, KEEP OFF, 

 Property of U. S. Coast and Geodetic Survey," that not only serves as a warning to 

 fishermen and curious yachtsmen, but also aids in the recovery of the apparatus if 

 the buoy should go adrift. These signs may be obtained from the Washington Office 

 on request. Ordinary buoys may be marked with the same sign or, if they are not, 

 they should be marked with a muslin "Signal Notice" (Form 51) tacked to the wooden 

 superstructure. 



282. Buoy Construction 



2821. Small Marker Buoy 



A 5-gallon gasoline (or oil) can, anchored by a light line or piece of stranded sound- 

 ing wire attached to a small anchor or grapnel, makes an admirable small marker buoy 

 for a launch hydrographic party. Such a buoy is light, occupies little space, and is 

 entirely satisfactory for temporary use in marking a shoal or other area during investiga- 

 tion. Any suitable object, a life ring or cork life preserver, may be substituted for 

 buoyancy. 



If additional visibility is required, the 5-gallon can may be secured to a light pole, 

 5 to 8 feet long, with a flag on the upper end and a counterweight on the lower end. 

 Such buoys have withstood heavy weather, and they are much more easily sighted 

 from a distance. 



