[American Sailing Association (ASA) 105 Coastal
Navigation exam with Questions and Answers/Plus a
Rationale Updated 2026 A+/Instant Download PDF
EXAM COVERAGE
1. Chart Symbols, Abbreviations, and Terminology
2. Plotting Tools and Techniques
3. Dead Reckoning (DR) and Estimated Position (EP)
4. Compass Corrections (Variation and Deviation)
5. Position Fixing (Lines of Position, Fixes, Running Fixes)
6. Current and Tidal Theory
7. Course to Steer and Set and Drift Calculations
8. Lights, Buoyage, and Aids to Navigation
9. Passage Planning and Weather Impacts
10. Electronic Navigation Integration
1. A navigator is plotting a course to steer and observes that the vessel's track is being consistently
pushed to the leeward of the intended track due to leeway. Given the vessel’s speed through the
water ($V_s$) is 6 knots and the leeway is estimated to be 10 degrees, what is the most
appropriate professional procedure to maintain the track?
A. Increase engine RPM to compensate for speed loss.
B. Apply a correction angle into the wind equal to the estimated leeway.
, C. Decrease engine RPM to reduce the impact of windage.
D. Alter course by 10 degrees to leeward to align the bow with the destination.
CORRECT ANSWER : B
Rationale: To maintain a desired track over ground while experiencing leeway, the navigator
must steer into the wind to counteract the drift. Option A does not correct the track; Option C is
irrelevant to track maintenance; Option D would increase the cross-track error.
2. You are calculating a Running Fix. The first bearing of a lighthouse is taken at 0800, and a
second bearing is taken at 0830. The vessel's Speed Over Ground (SOG) is 5 knots. What is the
distance the vessel has traveled between the two bearings?
A. 1.5 nautical miles
B. 2.0 nautical miles
C. 2.5 nautical miles
D. 3.0 nautical miles
CORRECT ANSWER : C
Rationale: The distance traveled is calculated by multiplying the speed by the time interval (5
knots × 0.5 hours = 2.5 nautical miles). Options A, B, and D are mathematically incorrect based
on the distance, speed, and time formula.
3. A navigator must determine the Compass Course (CC) to steer. Given True Course (TC) 090°,
Variation (V) 5° East, and Deviation (D) 3° West, what is the correct CC?
A. 082°
B. 088°
C. 092°
D. 098°
CORRECT ANSWER : B
Rationale: Applying "Can Dead Men Vote Twice" (Compass, Deviation, Magnetic, Variation,
True), we work backwards from True to Compass. TC (090°) - Var (5°E) = Magnetic Course
(085°). Magnetic Course (085°) - Dev (-3°W) = 088°. Other options result from improper sign
application.
,4. A vessel is navigating in a narrow channel with a known current setting 045° True at 2 knots.
The desired track is 090° True, and the planned speed through the water is 8 knots. Using a
vector triangle, what is the required course to steer (CTS) to maintain the track?
A. 078°
B. 082°
C. 098°
D. 102°
CORRECT ANSWER : B
Rationale: By constructing the vector triangle, the current vector (045° at 2 knots) is subtracted
from the desired track vector (090°). Calculating the resultant angle requires offsetting the
heading into the current; 082° provides the necessary compensation to offset the 045° set.
Options A, C, and D fail to achieve the required vector balance.
5. When using a sounding to establish a Line of Position (LOP) on a chart, why is it critical to
apply the current tide height correction?
A. To account for the variation between true and magnetic north.
B. To ensure the charted depth matches the depth relative to the chart datum.
C. To compensate for the vessel's draft and squat effects.
D. To eliminate the need for celestial observation.
CORRECT ANSWER : B
Rationale: Soundings are charted relative to a specific datum (usually MLLW). Without applying
the tidal height, the observed depth cannot be compared accurately to the chart's depth contour.
Options A, C, and D address unrelated navigation factors.
6. You are performing a three-point fix using horizontal sextant angles. The middle object is
located significantly closer to the observer than the two outer objects. What is the primary risk of
this specific geometry?
A. Excessive instrument error.
B. A "danger circle" scenario where the observer could be in a position of uncertainty.
C. Inability to read the sextant due to parallax.
, D. The calculation of the position becomes mathematically impossible.
CORRECT ANSWER : B
Rationale: When the middle object is closer than the others, the fix is susceptible to the "danger
circle" where the vessel's position may coincide with the circle passing through the three objects,
resulting in an indeterminate fix. Options A, C, and D are not inherent consequences of this
specific geometric configuration.
7. A vessel experiences an unexpected set of 15° to the right of the intended track over a period of 4
hours. If the distance traveled was 40 nautical miles, what is the cross-track error (XTE) at the
end of the 4 hours?
A. 5.2 nm
B. 8.4 nm
C. 10.4 nm
D. 12.2 nm
CORRECT ANSWER : C
Rationale: Using the formula $XTE = Distance \times \sin(Angle)$, the calculation is $40 \times
\sin(15^\circ)$, which equals approximately 10.35 nm. Options A, B, and D are incorrect results
of the trigonometric calculation.
8. When determining the "danger bearing" to avoid a shoal, what is the most professional
methodology?
A. Use the bearing of the furthest visible lighthouse.
B. Select a prominent charted object and identify the limiting bearing that marks the safe
limit.
C. Plot the bearing based on the estimated time of arrival.
D. Align the vessel with the sun's azimuth.
CORRECT ANSWER : B
Rationale: A danger bearing is a tactical tool using a charted landmark to define the edge of
safe water. Option A is unreliable; Option C is time-dependent rather than spatial; Option D is
inaccurate for coastal navigation.
Navigation exam with Questions and Answers/Plus a
Rationale Updated 2026 A+/Instant Download PDF
EXAM COVERAGE
1. Chart Symbols, Abbreviations, and Terminology
2. Plotting Tools and Techniques
3. Dead Reckoning (DR) and Estimated Position (EP)
4. Compass Corrections (Variation and Deviation)
5. Position Fixing (Lines of Position, Fixes, Running Fixes)
6. Current and Tidal Theory
7. Course to Steer and Set and Drift Calculations
8. Lights, Buoyage, and Aids to Navigation
9. Passage Planning and Weather Impacts
10. Electronic Navigation Integration
1. A navigator is plotting a course to steer and observes that the vessel's track is being consistently
pushed to the leeward of the intended track due to leeway. Given the vessel’s speed through the
water ($V_s$) is 6 knots and the leeway is estimated to be 10 degrees, what is the most
appropriate professional procedure to maintain the track?
A. Increase engine RPM to compensate for speed loss.
B. Apply a correction angle into the wind equal to the estimated leeway.
, C. Decrease engine RPM to reduce the impact of windage.
D. Alter course by 10 degrees to leeward to align the bow with the destination.
CORRECT ANSWER : B
Rationale: To maintain a desired track over ground while experiencing leeway, the navigator
must steer into the wind to counteract the drift. Option A does not correct the track; Option C is
irrelevant to track maintenance; Option D would increase the cross-track error.
2. You are calculating a Running Fix. The first bearing of a lighthouse is taken at 0800, and a
second bearing is taken at 0830. The vessel's Speed Over Ground (SOG) is 5 knots. What is the
distance the vessel has traveled between the two bearings?
A. 1.5 nautical miles
B. 2.0 nautical miles
C. 2.5 nautical miles
D. 3.0 nautical miles
CORRECT ANSWER : C
Rationale: The distance traveled is calculated by multiplying the speed by the time interval (5
knots × 0.5 hours = 2.5 nautical miles). Options A, B, and D are mathematically incorrect based
on the distance, speed, and time formula.
3. A navigator must determine the Compass Course (CC) to steer. Given True Course (TC) 090°,
Variation (V) 5° East, and Deviation (D) 3° West, what is the correct CC?
A. 082°
B. 088°
C. 092°
D. 098°
CORRECT ANSWER : B
Rationale: Applying "Can Dead Men Vote Twice" (Compass, Deviation, Magnetic, Variation,
True), we work backwards from True to Compass. TC (090°) - Var (5°E) = Magnetic Course
(085°). Magnetic Course (085°) - Dev (-3°W) = 088°. Other options result from improper sign
application.
,4. A vessel is navigating in a narrow channel with a known current setting 045° True at 2 knots.
The desired track is 090° True, and the planned speed through the water is 8 knots. Using a
vector triangle, what is the required course to steer (CTS) to maintain the track?
A. 078°
B. 082°
C. 098°
D. 102°
CORRECT ANSWER : B
Rationale: By constructing the vector triangle, the current vector (045° at 2 knots) is subtracted
from the desired track vector (090°). Calculating the resultant angle requires offsetting the
heading into the current; 082° provides the necessary compensation to offset the 045° set.
Options A, C, and D fail to achieve the required vector balance.
5. When using a sounding to establish a Line of Position (LOP) on a chart, why is it critical to
apply the current tide height correction?
A. To account for the variation between true and magnetic north.
B. To ensure the charted depth matches the depth relative to the chart datum.
C. To compensate for the vessel's draft and squat effects.
D. To eliminate the need for celestial observation.
CORRECT ANSWER : B
Rationale: Soundings are charted relative to a specific datum (usually MLLW). Without applying
the tidal height, the observed depth cannot be compared accurately to the chart's depth contour.
Options A, C, and D address unrelated navigation factors.
6. You are performing a three-point fix using horizontal sextant angles. The middle object is
located significantly closer to the observer than the two outer objects. What is the primary risk of
this specific geometry?
A. Excessive instrument error.
B. A "danger circle" scenario where the observer could be in a position of uncertainty.
C. Inability to read the sextant due to parallax.
, D. The calculation of the position becomes mathematically impossible.
CORRECT ANSWER : B
Rationale: When the middle object is closer than the others, the fix is susceptible to the "danger
circle" where the vessel's position may coincide with the circle passing through the three objects,
resulting in an indeterminate fix. Options A, C, and D are not inherent consequences of this
specific geometric configuration.
7. A vessel experiences an unexpected set of 15° to the right of the intended track over a period of 4
hours. If the distance traveled was 40 nautical miles, what is the cross-track error (XTE) at the
end of the 4 hours?
A. 5.2 nm
B. 8.4 nm
C. 10.4 nm
D. 12.2 nm
CORRECT ANSWER : C
Rationale: Using the formula $XTE = Distance \times \sin(Angle)$, the calculation is $40 \times
\sin(15^\circ)$, which equals approximately 10.35 nm. Options A, B, and D are incorrect results
of the trigonometric calculation.
8. When determining the "danger bearing" to avoid a shoal, what is the most professional
methodology?
A. Use the bearing of the furthest visible lighthouse.
B. Select a prominent charted object and identify the limiting bearing that marks the safe
limit.
C. Plot the bearing based on the estimated time of arrival.
D. Align the vessel with the sun's azimuth.
CORRECT ANSWER : B
Rationale: A danger bearing is a tactical tool using a charted landmark to define the edge of
safe water. Option A is unreliable; Option C is time-dependent rather than spatial; Option D is
inaccurate for coastal navigation.
