You observe the planet Jupiter at a sextant altitude (hs) of 66°27.6' on 26 May. The index error is 5.2' on the arc. The height of eye is 52 feet. What is the observed altitude (Ho)?

Correct Answer: Option A — 66°15.0'

Apply index error (on = add) to the sextant altitude. Subtract the dip correction for a 52-foot height of eye. Apply the planet altitude correction from the Nautical Almanac. The resulting observed altitude (Ho) is 66°15.0', adhering to the standard celestial navigation reduction procedures outlined in Bowditch.