Tonnage, Oceans Examination Practice

Coast Guard Third Mate – Unlimited Tonnage, Oceans Examination Practice Questions And Correct Answers (Verified Answers) Plus Rationales 2026 Q&A | Instant Download Pdf

• Which of the following is the primary purpose of the International

Regulations for Preventing Collisions at Sea (COLREGS)?

• To regulate ship construction standards
• To prevent collisions between vessels
• To manage maritime pollution
• To set shipping routes

Rationale: COLREGS provides rules for navigation and conduct to

prevent collisions at sea.

• When using a parallel ruler to transfer a course to a chart, you must

align the ruler with: 1 / 4

• A meridian or parallel line
• The nearest compass rose
• The equator
• A rhumb line

Rationale: Parallel rulers are used to transfer angles accurately

between the compass rose and the chart meridians or parallels.

• Which type of stability is concerned with a vessel returning to an

upright position after small angles of heel?

• Dynamic stability
• Initial stability
• Secondary stability
• Hydrostatic stability

Rationale: Initial stability refers to the vessel’s tendency to resist

small angles of heel and return upright.

4. The primary effect of wind on a vessel’s leeway is:

• Changing draft
• Pushing the vessel sideways
• Increasing speed
• Stabilizing the ship

Rationale: Wind causes leeway, a lateral movement of the vessel

away from its intended course.

• What is the minimum distance from shore a vessel must anchor in a

traffic separation scheme? 2 / 4

• 0.5 nautical miles
• As far as possible outside the scheme
• 1 nautical mile
• 2 nautical miles

Rationale: Anchoring is prohibited within traffic separation schemes

to avoid interference with traffic flow.

• A vessel is navigating in restricted visibility. The radar should be used

to:

• Only confirm the vessel’s position
• Avoid collision with other vessels and navigate safely
• Measure water depth
• Only detect land features

Rationale: Radar is a primary tool for detecting other vessels and

navigational hazards in restricted visibility.

7. The GM (metacentric height) is defined as:

• Distance between keel and center of gravity
• Distance between metacenter and keel
• Distance between center of gravity and metacenter
• Distance between waterline and center of buoyancy

Rationale: GM is a measure of initial stability, calculated as the

distance between the center of gravity (G) and the metacenter (M).

8. The standard International Load Line indicates:

• Maximum engine power 3 / 4

• Legal minimum freeboard
• Navigational speed
• Required fuel reserve

Rationale: Load lines indicate the maximum depth a vessel may be

loaded, ensuring safety and seaworthiness.

• Which of the following is a primary consideration in safe stowage of

cargo?

• Color of packaging
• Weight distribution and securing
• Insurance value
• Delivery schedule

Rationale: Proper weight distribution and secure stowage prevent

shifting that could affect stability or cause damage.

• When conducting a celestial fix, which star is preferred for

accuracy?

• Sirius
• Polaris
• Betelgeuse
• Vega

Rationale: Polaris (North Star) provides a reliable measurement of

latitude in the Northern Hemisphere.

11. The main function of a gyrocompass is to:

• Measure wind direction
• / 4