Piloting & Bearings Practice Questions

1. A navigator takes simultaneous bearings: Lighthouse A bears 000°T, Lighthouse B bears 090°T. The intersection of these two LOPs gives a:

• A.Running fix
• B.Estimated position
• C.DR position
• D.Fix✓

Why: When two or more LOPs are obtained simultaneously, their intersection is called a Fix — the most reliable type of position. A Running Fix uses LOPs from different times. An EP applies estimated current to a DR.

2. What is a danger bearing?

• A.The bearing to a hazard when it is directly ahead
• B.A limiting bearing beyond which a vessel must not go to safely clear a hazard✓
• C.A bearing taken to determine the distance off a shoal by vertical sextant angle
• D.The reciprocal of a vessel's true course when navigating in restricted waters

Why: A danger bearing is a bearing to a charted object that defines the limiting safe track. The bearing is labeled NMT (Not More Than) or NLT (Not Less Than) to indicate which side of the bearing is safe. The vessel must keep the object's bearing on the correct side of that limit.

3. Using the bow-and-beam bearing method, a vessel runs 6 nm between taking a 45° bow bearing and the abeam bearing on the same lighthouse. What is the approximate distance off the lighthouse when it is abeam?

• A.3.0 nm
• B.8.5 nm
• C.6.0 nm✓
• D.4.2 nm

Why: With the bow-and-beam method (first bearing 45° on the bow, second bearing abeam/90°), the distance off when abeam equals the distance run between bearings. Distance run = 6 nm, so distance off = 6.0 nm.

4. A vessel is on course 000°T and observes a lighthouse bearing 045°T at 1200. At 1230, the vessel has run 5 nm and the lighthouse now bears 090°T. What is the distance off the lighthouse at 1230?

• A.2.5 nm
• B.7.1 nm
• C.10.0 nm
• D.5.0 nm✓

Why: The relative bearing changed from 045° (45° on the bow) to 090° (abeam), so this is a bow-and-beam bearing. The angle was NOT doubled (45° to 90° is doubling of the complement angle). This is actually a bow-and-beam: distance off at abeam = distance run = 5.0 nm.

5. Which type of LOP provides the most accurate position line when obtained by radar in coastal piloting?

• A.Radar bearing on a point target
• B.Radar bearing on an extended shoreline
• C.Radar range on a diffuse coastline
• D.Radar range on an isolated point target✓

Why: Radar ranges on isolated, well-defined point targets (such as a small island, lighthouse, or prominent headland) produce the most accurate LOPs. Radar bearings are generally less accurate than ranges due to the wide beam width of most ship radars. Diffuse or extended targets introduce ambiguity.