ASA 105 Exam V1 2026-2027 |
Q&A & Verified Solutions | A+
Coastal Navigation Prep | Pass
Guaranteed
## PART A – MULTIPLE CHOICE (Q1–35)
* *Q1 (Chart symbols – buoy):** A buoy on a NOAA chart shows a red cylindrical shape with a
red light flashing every 4 seconds. The label reads "2". What is its significance?
. Starboard-hand daymark (green)
A
B. Port-hand nun buoy (red, even number)
C. Port-hand can buoy (red, even number)
D. Fairway buoy
**[CORRECT]** C
* Rationale: Red cylindrical (can) buoys are port-hand marks, kept to port when entering from
seaward. Even numbers on red buoys. Starboard buoys are conical (nun) and green (A).
Fairway buoys are striped (D). Test tip: "Red, Right, Returning" – but that is for red buoys on
starboard when returning; the description here is the buoy's shape and color – can = port.*
---
* *Q2 (Chart projections):** Which projection is used for standard NOAA nautical charts and
why?
. Gnomonic – because great circles appear as straight lines
A
B. Mercator – because rhumb lines appear as straight lines and angles are preserved
C. Polyconic – because it minimizes distortion in mid-latitudes
D. Lambert conformal – because it preserves area
**[CORRECT]** B
* Rationale: Mercator projection is standard for nautical charts because rhumb lines (lines of
constant bearing) plot as straight lines, making course plotting simple, and it preserves angles
,for bearings. Gnomonic is used for great circle route planning (A). Polyconic and Lambert are
not standard for coastal navigation charts (C, D). Test tip: Remember "Mercator = mariner" –
straight rhumb lines make plotting easy.*
---
* *Q3 (Chart scale):** A harbor chart has a scale of 1:20,000. A coastal chart has a scale of
1:80,000. Which statement is correct?
. The harbor chart covers a larger area with less detail
A
B. The coastal chart shows more detail for close-in navigation
C. The harbor chart shows greater detail for a smaller area
D. Both charts show the same level of detail
**[CORRECT]** C
* Rationale: A larger-scale chart (smaller denominator like 1:20,000) shows greater detail for a
smaller geographic area, ideal for harbor navigation. A smaller-scale chart (larger denominator
like 1:80,000) covers more area with less detail (A, B reversed). Test tip: "Large scale = large
detail, small area" – think of it as zooming in.*
---
* *Q4 (Compass conversion):** Your true course is 095°. The variation is 14°W. The deviation is
3°E. What is your compass course?
. 106°
A
B. 112°
C. 084°
D. 078°
**[CORRECT]** A
* Rationale: Using TVMDC+Add-West: True 095° – Variation 14°W (subtract west, add east) =
Magnetic 109°; then Magnetic 109° – Deviation 3°E (subtract east, add west) = Compass 106°.
Common error is adding west variation instead of subtracting (B), or confusing deviation
direction (C, D). Test tip: "Can Dead Men Vote Twice? At Elections" – Compass + Deviation =
Magnetic; Magnetic + Variation = True (add East, subtract West).*
---
* *Q5 (Compass bearings):** You take a bearing of a lighthouse and read 270° on your steering
compass. Variation is 10°E, deviation is 2°W. What is the true bearing?
, . 258°
A
B. 262°
C. 278°
D. 282°
**[CORRECT]** C
* Rationale: Compass 270° – Deviation 2°W (subtract west) = Magnetic 268°; Magnetic 268° +
Variation 10°E (add east) = True 278°. Using CDMVT: C 270° – D 2°W = M 268° + V 10°E = T
278°. Common error is reversing the operations (A, B) or adding deviation (D). Test tip: When
converting compass to true, work from bottom to top of the memory aid (C-D-M-V-T).*
---
**Q6 (Variation):** Variation is the angle between:
. True north and compass north
A
B. Magnetic north and compass north
C. True north and magnetic north
D. The lubber line and the compass card
**[CORRECT]** C
* Rationale: Variation is the angular difference between true north (geographic North Pole) and
magnetic north (Earth's magnetic pole), caused by the Earth's magnetic field. Deviation is
between magnetic and compass north (B). The lubber line indicates the vessel's heading (D).
Test tip: "Variation is from the Earth, Deviation is from the boat" – remember V=geographic,
D=local magnetic disturbances.*
---
* *Q7 (Parallel rulers):** When transferring a course line from the compass rose to your chart
using parallel rulers, the correct technique is to:
. Walk the rulers across the chart in one motion without lifting
A
B. Lift and reset the rulers in small increments, maintaining parallel alignment
C. Use only one ruler and estimate the parallel line
D. Draw the line first, then align the rulers afterward
**[CORRECT]** B
* Rationale: Parallel rulers are walked across the chart by alternately holding one ruler steady
while moving the other, maintaining parallel alignment through small increments. Walking in one
Q&A & Verified Solutions | A+
Coastal Navigation Prep | Pass
Guaranteed
## PART A – MULTIPLE CHOICE (Q1–35)
* *Q1 (Chart symbols – buoy):** A buoy on a NOAA chart shows a red cylindrical shape with a
red light flashing every 4 seconds. The label reads "2". What is its significance?
. Starboard-hand daymark (green)
A
B. Port-hand nun buoy (red, even number)
C. Port-hand can buoy (red, even number)
D. Fairway buoy
**[CORRECT]** C
* Rationale: Red cylindrical (can) buoys are port-hand marks, kept to port when entering from
seaward. Even numbers on red buoys. Starboard buoys are conical (nun) and green (A).
Fairway buoys are striped (D). Test tip: "Red, Right, Returning" – but that is for red buoys on
starboard when returning; the description here is the buoy's shape and color – can = port.*
---
* *Q2 (Chart projections):** Which projection is used for standard NOAA nautical charts and
why?
. Gnomonic – because great circles appear as straight lines
A
B. Mercator – because rhumb lines appear as straight lines and angles are preserved
C. Polyconic – because it minimizes distortion in mid-latitudes
D. Lambert conformal – because it preserves area
**[CORRECT]** B
* Rationale: Mercator projection is standard for nautical charts because rhumb lines (lines of
constant bearing) plot as straight lines, making course plotting simple, and it preserves angles
,for bearings. Gnomonic is used for great circle route planning (A). Polyconic and Lambert are
not standard for coastal navigation charts (C, D). Test tip: Remember "Mercator = mariner" –
straight rhumb lines make plotting easy.*
---
* *Q3 (Chart scale):** A harbor chart has a scale of 1:20,000. A coastal chart has a scale of
1:80,000. Which statement is correct?
. The harbor chart covers a larger area with less detail
A
B. The coastal chart shows more detail for close-in navigation
C. The harbor chart shows greater detail for a smaller area
D. Both charts show the same level of detail
**[CORRECT]** C
* Rationale: A larger-scale chart (smaller denominator like 1:20,000) shows greater detail for a
smaller geographic area, ideal for harbor navigation. A smaller-scale chart (larger denominator
like 1:80,000) covers more area with less detail (A, B reversed). Test tip: "Large scale = large
detail, small area" – think of it as zooming in.*
---
* *Q4 (Compass conversion):** Your true course is 095°. The variation is 14°W. The deviation is
3°E. What is your compass course?
. 106°
A
B. 112°
C. 084°
D. 078°
**[CORRECT]** A
* Rationale: Using TVMDC+Add-West: True 095° – Variation 14°W (subtract west, add east) =
Magnetic 109°; then Magnetic 109° – Deviation 3°E (subtract east, add west) = Compass 106°.
Common error is adding west variation instead of subtracting (B), or confusing deviation
direction (C, D). Test tip: "Can Dead Men Vote Twice? At Elections" – Compass + Deviation =
Magnetic; Magnetic + Variation = True (add East, subtract West).*
---
* *Q5 (Compass bearings):** You take a bearing of a lighthouse and read 270° on your steering
compass. Variation is 10°E, deviation is 2°W. What is the true bearing?
, . 258°
A
B. 262°
C. 278°
D. 282°
**[CORRECT]** C
* Rationale: Compass 270° – Deviation 2°W (subtract west) = Magnetic 268°; Magnetic 268° +
Variation 10°E (add east) = True 278°. Using CDMVT: C 270° – D 2°W = M 268° + V 10°E = T
278°. Common error is reversing the operations (A, B) or adding deviation (D). Test tip: When
converting compass to true, work from bottom to top of the memory aid (C-D-M-V-T).*
---
**Q6 (Variation):** Variation is the angle between:
. True north and compass north
A
B. Magnetic north and compass north
C. True north and magnetic north
D. The lubber line and the compass card
**[CORRECT]** C
* Rationale: Variation is the angular difference between true north (geographic North Pole) and
magnetic north (Earth's magnetic pole), caused by the Earth's magnetic field. Deviation is
between magnetic and compass north (B). The lubber line indicates the vessel's heading (D).
Test tip: "Variation is from the Earth, Deviation is from the boat" – remember V=geographic,
D=local magnetic disturbances.*
---
* *Q7 (Parallel rulers):** When transferring a course line from the compass rose to your chart
using parallel rulers, the correct technique is to:
. Walk the rulers across the chart in one motion without lifting
A
B. Lift and reset the rulers in small increments, maintaining parallel alignment
C. Use only one ruler and estimate the parallel line
D. Draw the line first, then align the rulers afterward
**[CORRECT]** B
* Rationale: Parallel rulers are walked across the chart by alternately holding one ruler steady
while moving the other, maintaining parallel alignment through small increments. Walking in one
