USCG Exam PracticeDead reckoning — DR plot maintenance
A new DR position must be plotted at every course change, every speed change, at each fix, and ______.
- A. at every change of watch
- B. whenever visibility drops below 1 mile
- C. whenever depth changes by 10 fathoms
- ✓ at least once each hourCorrect
Why D is correct
DR positions are required at course changes, speed changes, each fix, and at minimum once per hour — with greater frequency required in pilot waters.
Cited:Bowditch Ch. 8 §801