Fog Signal Distance Finding for Boston Lightship (1953)

For 2 minutes For 1 minute
  RBN Off 52
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1
 
1
 
1
 
5
 
  FS
17 3
 
17 3
 
17 3
 
17 3
 
33
 
 
1
 
1
 
5
 
Figures show seconds.
 
 Shows of dash of RBN or
 blast of fog signal.
RBN Code: