Fog Signal Distance Finding for Halfway Rock (1953)

For 2 minutes For 1 minute
  RBN Off 52
<––––Code––––>
1
 
1
 
1
 
5
 
  FS
51 3
 
3 3
 
53
 
 
1
 
1
 
5
 
Figures show seconds.
 
 Shows of dash of RBN or
 blast of fog signal.
RBN Code: