USCG Exam PracticePlotting with variation and deviation (T-V-M-D-C)
When operating a vessel with a magnetic compass, a person directing and controlling the movement of a towing vessel is required to know and apply which of the following?
- ✓ Variation and deviation, where charts have enough detail to enable this correctionCorrect
- B. Variation only, as deviation is accounted for by the compass manufacturer
- C. Deviation only, as variation is printed on the chart rose and applied automatically
- D. Neither variation nor deviation, as GPS renders compass correction unnecessary
Why A is correct
33 CFR §164.78(a)(5) requires that the person directing and controlling a towing vessel knows and applies the variation and deviation where a magnetic compass is fitted and where charts or maps have enough detail to enable this type of correction. Both corrections must be applied.
Cited:33 CFR §164.78