🔍 Key Concepts

• High altitude sun sights and how they affect sight reduction accuracy • The role of refraction and dip corrections at different altitudes • Practical vs. theoretical problems in using a sextant at very high altitudes

💭 Think About

• Think about what physically changes when the Sun is very high in the sky and how that affects the reliability of your measured altitude and the corrections you apply. • Ask yourself which of the options describes an issue that becomes worse specifically at high altitudes, not one that would be the same at low or moderate altitudes. • Consider whether the main difficulty is about using the sextant itself, the stability of the reading, or the accuracy of the correction tables you must apply.

✅ Before You Answer

• Identify which choices describe problems that would occur at any altitude, not just high ones—these are less likely to be the unique ‘major problem’. • Check which option is tied to how well correction tables or refraction assumptions work when the observed altitude is very large. • Make sure the choice you pick is clearly linked to a change in observation or correction quality that is unique to high altitudes.