The refraction correction table given in the Nautical Almanac is based on a standard or average atmospheric density with a temperature of 50°F (10°C) and atmospheric pressure of __________.
Official USCG Answer & Rule Citation
Correct Answer: Option B — 29.83 inches (1010 millibars)
The Nautical Almanac refraction correction tables are standardized for an atmospheric pressure of 29.83 inches of mercury (1010 millibars) and a temperature of 50ÞgF (10ÞgC), requiring corrections for non-standard meteorological conditions.
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