AIDS TO NAVIGATION 83 



LIGHTSHIPS (Fig. 24) (K-6) 



Characteristics of lighits on lightships shall include the height of the light and its visibility. 

 The position of a lightship is indicated on the chart by the small circle at the base of the symbol. 

 This circle is to be overprinted on the final chart by a magenta disc 3.0 ram. in diameter. 

 Names of lightships should be in Draftsman's Italic. Correct charting of a lightship is illus- 

 trated on Figure 24 in the Appendix. 



STATION BUOYS 



A station buoy is anchored close to a lightship, or to an important buoy, to mark the posi- 

 tion in case the regular aid is carried away. The station buoy has the same color as the regular 

 aid. Lightship station buoys bear the letters L.S. above the initials of the station. Station 

 buoys are not to be shown on the charts. 



LIGHTFLOATS (1^12) 



Floats which display lights should be indicated on the chart by the lighted open buoy 

 symbol and labeled "float." 



LIGHT SECTOR (Fig. 1) (K-12; P-4) 



A Light Sector is an arc of a circle bounded by two radii in which a light is visible. The 

 length of the dotted line used to indicate the Umits of a Light Sector should generally cor- 

 respond to the visibihty given in the Light List. Thus, if a hght's visibility is 20 miles, the 

 length of the ray Unes should be 20 miles at the scale of the chart. 



Limits of sectors and arcs of visibUity are given in the Light List in degrees in a clockwise 

 direction from seaward toward the light. 



Colors of sectors are labeled in the form of an arc of a circle about one inch away from 

 the light. For red sectors, a magenta line should be shown under the words "red sector." 



HORN 



A horn, bell, gong, or siren, not accompanying a regular aid, should be indicated on the 

 chart by a small circle symbol. The name should be in caps, using 6 pt. No. 3 LightUne Gothic 

 style of type: o horn 



