Marina Exam Reviewer: Two navigational hazards are located near to each other, but each marked by an individual cardinal buoyage system. The buoys of one cardinal system may be identified from the other system by __.

Marina Exam Reviewer

Two navigational hazards are located near to each other, but each marked by an individual cardinal buoyage system. The buoys of one cardinal system may be identified from the other system by __. 

A. one system using horizontal bands while the other system uses vertical stripes 
B. the differing light colors 
C. the difference in the periods of the light 
D. one system having odd numbers while the other system has even numbers 


Answer:       C. the difference in the periods of the light 

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