215 HYDROGRAPHIC MANUAL PaGE 64 



streets, roads, or other features; and their heights and structural appearances. A 

 description such as "Water Tank, Port Angeles, Washington," is inadequate and not 

 acceptable. Ten or twenty years later a new survey may be made in the vicinity and 

 there may be two water tanks in the locality where only one was expected. There 

 will be doubt as to which was the one located. Still worse is the possibility that there 

 may be only one water tank in the town, as expected, but the described water tank 

 has been torn down since the prior survey and a new one erected in an adjacent location. 

 If this is not known and the water tank is used as a control station in a hydrographic 

 survey, before its position is checked, serious errors may result. 



All objects of a recoverable nature, particularly lighthouses, church spires, cupolas, 

 towers, stacks, flagpoles, etc., whose positions are worth determining are considered to 

 be of sufficient importance to require descriptions, especially if they serve as land- 

 marks or will be of value as control stations for future hydrographic surveys. To 

 obtain adequate data for a description, it is essential to visit the site of the object to 

 be described. Likewise, when objects of this type, whose positions have been deter- 

 mined by prior surveys, are used for the control of revision or new surveys, each site 

 should first be visited for positive identification, and to establish beyond doubt that it 

 has not been moved in location since the date of the original description. The neces- 

 sary information may sometimes be obtained by correspondence or by personal inquiries 

 from reliable sources, but certam identification is assured only by an actual visit to 

 the site. 



Unmarked whitewashes, banners, clumps of bushes, and signals located for tempo- 

 rary use in hydrographic surveys are, of course, not recoverable stations and need not 

 be described. 



215. Control Station Names 



For purposes of identification and convenient reference, names are assigned to 

 the control stations used in a hydrographic survey. In the assignment and use of such 

 names, the following general principles should be observed, irrespective of the type of 

 station being considered (see 2151): 



(0) All references to a station shall be by the name assigned to it. 



(6) The same name shall be retained for a station during its existence or as long as it is used. 



(c) Different names shall never be assigned to the same station, even in different surveys. 



(d) Descriptive, geographic, or personal names which contain a natural reference to the station 

 are preferable to arbitrary ones (see 2151). For example, where a station is on or near a named geo- 

 graphic feature, or is an artificial object such as a spire or tank. 



(e) Recovered stations used in a survey shall always retainthe original names assigned to them, 

 except in the case of triangulation stations with unnecessarily long names, when a short name may 

 be substituted for hydrographic use. The new name may consist of syllables of the original name 

 (e. g., NIKOL for NIKOLSKI, 1938). (See 2154 and 744.) 



(/) A duplication of names must be avoided in the same locality and especially within the limits 

 of the same hydrographic sheet. 



2151. Types of Station Names 



The length of an arbitrary name assigned to a control station shall reflect in a 

 general way the relative importance of the station named. Certain definite advan- 

 tages accrue from such a system of naming. To accomplish the purpose, names for 

 the various types of control stations shall be selected in accordance with the following 

 rules : 



(1) Names of five or more letters — triangulation and traverse stations. 



(2) Names op four letters — marked topographic stations; sono-radio buoys; R.A.R. shore 



