Question 820Navigation General

The correct answer is C) prismatic error. The explanation is as follows: The seven errors associated with the marine sextant are index error, perpendicularity of the horizon glass, perpendicularity of the index mirror, side error, shimmer error, prismatic error, and eccentricity error. Out of these, the prismatic error is not correctable by the navigator, as it is caused by the prism in the sextant and requires adjustments by a trained technician. The other errors, such as index error, perpendicularity of the horizon glass, and perpendicularity of the index mirror, can be corrected by the navigator through proper calibration and adjustment of the sextant.