64 



UNITED STATES COAST GUARD 



6. COMPASS DEVIATION. 



Enroute from Philadelphia to Liver- 

 pool, in D. R. Latitude 42°-00' North 

 and Longitude 50°-00' West, an azi- 

 muth of the star 7 (Gamma) Ursa 



Minoris was observed. The following 

 data was obtained at the time of obser- 

 vation : 



Compass Bearing Of Star 



28°-00' psc 



Greenwich Hour Angle 



255°-55'.6 



Declination Of Star 



71°-59'.l N. 



Variation for the locality was 24''-36'.0 

 West 



Required: 



The true azimuth. 



The deviation of the standard com- 

 pass. 



Candidates may use any method of 

 solution. 



11. PILOTING. 



Your vessel is steering 283" True, a 

 light is sighted bearing 219° p.s.c, vari- 

 ation 23° East, deviation 1° East. On 

 what compass bearing must the light be 

 again observed so that the run be- 

 tween bearings will equal the distance 

 off when the light bears 193° True? 



On course 104° p.g.c, gyro error 1° 

 West, a light is sighted bearing 113° 

 p.s.c, variation 23° East, deviation 1° 

 West. On what gyro bearing must the 

 light be observed so that the run be- 

 tween bearings will equal the distance 

 off when the light bears 194° p.g.c? 



On course 283° True, a light is sighted 

 bearing 228° p.s.c, variation 23° East, 

 deviation 3° East. On what bearing 

 must the light be observed so that the 



run between bearings will equal the dis- 

 tance off when the light bears 167° 

 p.s.c? 



A ship is steering 101° p.g.c, vari- 

 ation 23° East, deviation 3° West, 

 which is 82 ° p.s.c. A light is sighted 

 bearing 129° True. On what gyro bear- 

 ing must the light be observed so 

 that the run between bearings would 

 equal the distance off when the light 

 bears 191° gyro? 



It is desired to avoid coming closer 

 than within 0.8 miles of a light listed as 

 110 feet above high water level. Deter- 

 mine the proper vertical danger angle 

 in this case and state how you would 

 use it. 



Note: Problems may be given pertaining to piloting which are under other titles in this book. 



12. AIDS TO NAVIGATION. 



How are arcs of visibility and limits 

 of a light given in a light list? 



From what reference point is the 

 height of a light measured? 



Describe how light phase characteris- 

 tics are assigned to buoys in the lateral 

 system of buoyage of the United States. 



What action should be taken if a 

 light is found to be extinguished or any 

 other defect is noted in its operation? 



How may the color of a light be af- 

 fected by atmospheric conditions? 



What is the purpose of international 

 numbers assigned to major seacoast 

 lights in the light list? 



What is indicated by the white and 

 black alternate horizontally banded 

 buoy sketched? 



imriE 



BUCK 



TOIITE 



