INSTRUCTIONS TO MARINE METEOROLOGICAL OBSERVERS HQ 



EAST LONGITUDE, P M., CIVIL DATE 



Table 10. — Distance of visiMUty of objects at sea {in natctical miles) 



Height of 

 observer's 

 eye above 

 sea level 

 (in leet) 



10_ 

 15- 

 20- 

 25. 

 30. 

 35. 

 40. 

 45. 

 50. 

 60. 

 70. 

 80. 

 90. 

 100 



Height of object above sea level (in feet) 



7.2 



8.0 



8.7 



9.3 



9.9 



10.4 



10.8 



11.3 



11.7 



12.5 



13.2 



13.9 



14.5 



15.1 



8.7 

 9.5 

 10.2 

 10.8 

 11.4 

 11.9 

 12.3 

 12.8 

 13.2 

 14.0 

 14.7 

 15.4 

 16.0 

 16.6 



9.9 

 10.7 

 11.4 

 12.0 

 12.6 

 13.1 

 13.5 

 14.0 

 14.4 

 15.2 

 15.9 

 16.6 

 17.2 

 17.8 



10.8 

 11.6 

 12.3 

 12.9 

 13.5 

 14.0 

 14.4 

 14.9 

 15.3 

 16.1 

 16.8 

 17.5 

 18.1 

 18.7 



12.5 

 13.3 

 14.0 

 14.6 

 15.2 

 15.7 

 16.1 

 16.6 

 17.0 

 17.8 

 18.5 

 19.2 

 19.8 

 20.4 



80 



13.9 

 14.7 

 15.4 

 16.0 

 16.6 

 17.1 

 17.5 

 18.0 



100 150 



15.1 

 15.9 

 16.6 

 17.2 

 17.8 

 18.3 

 18.7 

 19.2 

 19.6 

 20.4 

 21. 1 

 21.8 

 22.4 

 23.0 



17.7 

 18.5 

 19.2 

 19.8 

 20.4 

 20.9 

 21.3 

 21.8 

 22.2 

 23.0 

 23.7 

 24.4 

 25.0 

 25.6 



200 



19.8 

 20.6 

 21.3 

 21.9 

 22.5 

 23.0 

 23.4 

 23.9 

 24.3 

 25.1 

 25.8 

 26.5 

 27. 1 

 27.7 



300 



23.5 

 24.3 

 25.0 

 25.6 

 26.2 

 26.7 

 27.1 

 27.6 

 28.0 

 28.8 

 29.5 

 30.2 

 30.8 

 31.4 



400 600 



I 



26.5 

 27.3 

 28.0 

 28.6 

 29.2 

 29.7 

 30.1 

 30.6 

 31.0 

 31.8 

 32.5 

 33.2 

 33.8 

 34.4 



3L6 

 32.4 

 33.1 

 33.7 

 34.3 

 34.8 

 35.2 

 35.7 

 36.1 

 36.9 

 37.6 

 38.3 

 38.9 

 39.5 



36.0 

 36.8 

 37.5 

 38.1 

 38.7 

 39.2 

 39.6 

 40.1 

 40.5 

 41.3 

 42.0 

 42.7 

 43.3 

 43.9 



1,000 



39.8 

 40.6 

 41.3 

 41.9 

 42.5 

 43.0 

 43.4 

 43.9 

 44.3 

 45.1 

 45.8 

 46.5 

 47.1 

 47.7 



