What is the observation order for NAV aids when making a fix?

• A. Bow, Beam, Stern
• B. Bow, Stern, Beam
• C. Stern, Bow, Beam
• D. Beam, Bow, Stern

Answer: (B)

When you’re making a fix using NAV aids, you determine your position by drawing lines of position (LOP) from at least three known aids. The order you observe them matters for getting a clean, accurate intersection on the chart. Starting with a NAV aid to the bow is ideal because it’s typically the easiest to sight clearly with minimal hull obstruction and without the ship’s own motion affecting the bearing too much. Next, taking a bearing to a NAV aid toward the stern adds a second line of position with a different geometry, which helps separate measurement errors from the true intersection. Finally, observing a NAV aid at the beam provides a third line that crosses the other two in a way that gives a robust, well-defined fix; having a line roughly 90 degrees from the first two improves the geometric cross-check and helps reveal any inconsistent bearing. With three well-spaced lines of position, you can plot a precise intersection on the chart.

Other sequences tend to produce less favorable geometry or involve bearings that are harder to observe accurately due to hull clearance or motion, making the fix less reliable.