Coast Guard Exams
Question 117Navigation Problems70% to pass

You observe the lower limb of the Sun at a sextant altitude (hs) of 46°20.3' on 1 April. The index error is 4.5' off the arc. The height of eye is 57 feet (17.4 meters). What is the observed altitude (Ho)?

AI Explanation
The correct answer is D) 46°32.6'. The observed altitude (Ho) is calculated by adding the sextant altitude (hs) and the index error. In this case, the sextant altitude is 46°20.3' and the index error is 4.5' off the arc, which means the index error is added to the sextant altitude. Therefore, the observed altitude (Ho) is 46°20.3' + 4.5' = 46°24.8'. The other answer choices are incorrect because they do not correctly account for the index error. Option A) 46°24.2' does not include the index error, option B) 46°30.1' and option C) 46°27.9' include the index error incorrectly.

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