Question 1

Offshore, the steering compass is checked against…

Accepted Answer

A celestial body — compare its compass bearing with the azimuth the sight reduction computes — The computed azimuth (Zn) is truth from astronomy; bearing the body and comparing reveals the compass error on that heading — no shore marks needed.

Question 2

The amplitude method checks the compass using…

Accepted Answer

The sun as it rises or sets — its bearing then is computable from declination and latitude alone — At rising/setting the geometry simplifies: true bearing ≈ 90° ± offsets driven by declination and latitude. A horizon sun is also the easiest bearing to take.

Checking the compass by the sky

This lesson is part of a paid course