A 4530N, 12415W - Practice Exam Questions And Correct Answers (Ve...

Coast Guard Mate 500 GRT Near Coastal Practice Exam Questions And Correct Answers (Verified Answers) Plus Rationales 2026 Q&A | Instant Download Pdf

• A vessel is at 45°30'N, 123°15'W. If it sails 60 nautical miles due east,

what is its approximate new position?

A) 45°30'N, 124°15'W

B) 45°30'N, 122°15'W

C) 46°00'N, 123°15'W

D) 44°30'N, 123°15'W

Rationale: Moving east or west changes longitude, not latitude. 1°

longitude ≈ 60 NM at the equator; near 45° latitude, correction is minor.

• Which type of chart projection is most commonly used for marine

navigation?

• Polyconic
• Gnomonic 1 / 4

• Mercator
• Lambert

Rationale: Mercator charts preserve angles and shapes for navigation,

making them standard for coastal and offshore plotting.

• What is the primary purpose of a compass deviation table?
• To correct for variation
• To correct for deviation
• To adjust course for current
• To compute set and drift

Rationale: Deviation is the compass error caused by the vessel’s magnetic

field; the deviation table provides the necessary corrections.

• The magnetic compass shows 045° and the deviation is +2°, variation

10°W. What is the true course?

A) 057°

B) 033°

C) 053°

D) 057°

Rationale: True Course = Compass + Deviation + Variation. 045 + 2 + 10 =

057°.

• How is a vessel’s position most accurately determined?
• Dead reckoning
• Fixing with two or more bearings 2 / 4

• Estimated position
• GPS only

Rationale: Fixing with multiple bearings provides the most accurate

position; dead reckoning is less reliable due to cumulative errors.

6. The term “set and drift” refers to:

• Current direction and speed
• Wind speed and direction
• Tide height variations
• Compass error

Rationale: Set is the direction of the current, drift is its speed.

• What is the main advantage of GPS over traditional navigation

methods?

• No need for charts
• Eliminates all errors
• Precise global positioning
• Predicts tides

Rationale: GPS provides accurate positioning regardless of visibility or

other navigational references.

• When plotting a course using a parallel ruler, the ruler is primarily

used to:

• Measure distances
• Determine speed 3 / 4

• Transfer a course line to the compass rose
• Correct for deviation

Rationale: The parallel ruler allows the navigator to maintain parallel lines

when transferring bearings or courses.

• Which type of buoy indicates the starboard side of a channel when

entering from seaward?

• Green
• Red
• Yellow
• Black

Rationale: In the IALA Region B system, green buoys mark starboard when

entering from sea.

10. When approaching a narrow channel, a vessel should:

• Sound one prolonged blast
• Keep to the starboard side of the channel
• Maintain full speed
• Anchor if unsure

Rationale: Navigation rules require vessels to keep to the starboard side to

prevent collisions in narrow channels.

Rules of the Road (COLREGS)

• / 4