🔍 Key Concepts

• Moon sight corrections in the Nautical Almanac (what each table is designed to correct) • Difference between instrument-related errors and astronomical/geometric corrections • What typical Moon correction tables already combine: parallax, semidiameter, and augmentation

💭 Think About

• Ask yourself: Which option depends on your specific sextant and handling, rather than on the Moon’s position and the Earth–Moon geometry? • Think about which corrections the Nautical Almanac can precompute for everyone, versus which ones each navigator must determine and apply individually. • Review what is meant by parallax, semidiameter, and augmentation for the Moon—are these fixed astronomical effects or user-specific effects?

✅ Before You Answer

• Identify which choice refers to an error that varies from one sextant to another, and even from one observation to the next. • Confirm which corrections the Nautical Almanac can tabulate in advance because they depend only on time and approximate observer location (not on your particular instrument). • Make sure you know that Moon altitude correction tables already bundle certain lunar effects together—check which of the listed items are normally included in those combined corrections.