1
ASA 105 Coastal Navigation Exam V2 Actual
Exam 2026/2027 | Complete Exam-Style
Questions | 100% Verified – Detailed
Rationales – Pass Guaranteed – A+ Graded
TABLE OF CONTENTS
Section 1 | Nautical Charts and Publications | Q1 – Q13
Section 2 | Plotting and Dead Reckoning | Q14 – Q25
Section 3 | Tides, Currents, and Weather | Q26 – Q37
Section 4 | Navigation Instruments and Electronic Navigation | Q38 – Q50
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════════════
SECTION 1: NAUTICAL CHARTS AND PUBLICATIONS
═══════════════════════════════════════════════════════
════════════
Question 1 of 50
Your vessel is approaching the entrance to Chesapeake Bay from the Atlantic Ocean at 0800 on a
clear morning. You are using NOAA Chart 12221 and notice a magenta dashed line running
parallel to the entrance channel with the label "Safety Contour 18 ft." You need to determine the
minimum depth you can expect when crossing this contour line on a falling tide, given that the
charted depth in the adjacent channel is 22 feet and the tide range is 3.5 feet.
A. The safety contour indicates a dredged channel maintained at exactly 18 feet at all tidal
stages.
B. The safety contour marks the boundary where depths are less than 18 feet at the lowest
astronomical tide, so actual depth may vary.
C. The safety contour represents the 18-foot depth line at mean lower low water, providing a
conservative reference for safe passage. ✓ CORRECT
D. The safety contour is a historical reference only and does not reflect current survey data for
navigation purposes.
Correct Answer: C
,2
Rationale: The safety contour on modern NOAA charts is referenced to the chart datum, which
for the U.S. East Coast is typically mean lower low water (MLLW), meaning the 18-foot contour
indicates areas where 18 feet of depth can be expected at or below that tidal datum. Option A is
incorrect because safety contours are not guarantees of maintained dredged depth but rather
hydrographic representations based on soundings reduced to chart datum. Mariners should
always verify that their vessel's draft plus required under-keel clearance does not exceed the
available depth after accounting for tide height above chart datum.
Question 2 of 50
While planning a coastal passage from Newport, Rhode Island to Block Island, you consult
NOAA Chart 13209 and the accompanying Coast Pilot. You observe a symbol on the chart
depicting a black square with a dot in the center located on a prominent headland. You need to
identify this aid to navigation and determine its primary purpose for your daylight approach.
A. It indicates a lighted buoy with a horn sounding every 30 seconds for fog navigation.
B. It represents a daybeacon with no lateral significance, used to mark a specific navigational
feature or hazard. ✓ CORRECT
C. It denotes a radar reflector installed on an uncharted obstruction for electronic navigation.
D. It signifies a temporary floating mark placed by local fishermen to indicate lobster trap
locations.
Correct Answer: B
Rationale: A black square with a central dot is the standard chart symbol for a daybeacon, which
is an unlighted fixed aid to navigation typically used to mark hazards, channels, or specific
geographic features without conveying lateral channel significance. Option A is tempting
because many aids have lights, but the symbol specifically lacks the magenta flare or light
characteristic notation that would indicate a lighted aid. Daybeacons are essential reference
points for visual piloting, particularly when cross-bearing with other fixed objects to confirm
vessel position near rocky coastlines.
Question 3 of 50
You are preparing for a voyage from San Francisco Bay to Monterey Bay and are reviewing the
chart catalog to select appropriate paper charts. You note that NOAA Chart 18680 covers the
entire route at a scale of 1:200,000, while Chart 18685 covers only the approach to Monterey
Harbor at 1:40,000. You need to determine which chart would provide the most detailed depth
soundings and shoreline features for the final harbor approach.
A. Chart 18685 at 1:40,000 will display significantly greater detail including individual rocks,
small-craft anchorages, and precise depth curves. ✓ CORRECT
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B. Chart 18680 at 1:200,000 is superior for harbor approach because larger scale charts always
show more navigational detail.
C. Both charts contain identical sounding data because NOAA uses the same survey resolution
for all coastal charts regardless of scale.
D. Chart 18680 should be used exclusively because it covers the entire route, eliminating the
need to switch charts during the passage.
Correct Answer: A
Rationale: Nautical chart scale is expressed as a ratio where a smaller denominator indicates a
larger scale chart; thus 1:40,000 is a larger scale than 1:200,000 and will show more detailed
soundings, smaller geographic features, and precise navigation aids in the harbor approach.
Option B confuses the terminology—mariners often mistakenly believe "larger scale" means a
bigger number, when in fact it means a smaller ratio denominator representing more detail per
unit area. Always transition to the largest scale chart available when making a harbor approach to
ensure you can identify all hazards and navigation marks.
Question 4 of 50
While transiting the Intracoastal Waterway near St. Augustine, Florida, you encounter a junction
buoy marked on NOAA Chart 11485 with a horizontal band of red and green. Your vessel is
proceeding southbound in the waterway and must determine the proper course of action when
approaching this aid from the north.
A. Keep the buoy to starboard regardless of direction of travel because red marks the right side
of the channel.
B. Pass close aboard to port because green always indicates the edge of safe water on your port
side.
C. Alter course to avoid the mark entirely, as junction buoys indicate submerged wrecks and
should never be approached.
D. Treat the buoy as a preferred channel mark where the top color indicates the preferred channel
for your direction of travel. ✓ CORRECT
Correct Answer: D
Rationale: A junction buoy with horizontal red and green bands is a preferred channel mark
where the top band indicates the preferred channel; when proceeding southbound, the top color
determines whether you leave it to port or starboard based on the "red right returning"
convention applied to the preferred channel. Option A is incorrect because it ignores the dual-
color nature of the mark and the fact that the top color governs the preferred channel indication,
not simply the presence of red. Junction buoys require careful observation from a distance to
, 4
correctly identify the top color, as misidentification in poor visibility can lead to grounding on a
shoal at the channel intersection.
Question 5 of 50
Your vessel is anchored in Puget Sound and you are reviewing the Local Notice to Mariners to
check for chart corrections published within the last month. You find an entry stating "Chart
18441, permanent change, reposition lighted buoy PG '3' to 47°43.2'N, 122°31.8'W." You need to
apply this correction to your paper chart using the standard method prescribed by NOAA.
A. Use a pencil to lightly mark the new position and note the correction date in the chart title
block.
B. Apply correction fluid to remove the old buoy position, then ink in the new location and erase
the fluid after drying.
C. Use a fine-point permanent pen to ink in the new buoy position, draw a connecting line from
the old position if nearby, and record the Notice number and date in the lower left margin. ✓
CORRECT
D. Write the correction details only in the vessel's logbook, as chart corrections should never be
marked directly on the chart.
Correct Answer: C
Rationale: Standard NOAA protocol requires that permanent chart corrections be applied in
permanent ink to ensure they are not accidentally erased, with the correction source documented
in the chart margin to maintain traceability and indicate when the chart was last updated. Option
A is incorrect because pencil marks can be erased by moisture or handling, potentially leaving
the navigator with outdated information during a critical passage. Maintaining properly corrected
charts is a legal requirement for commercial vessels and a critical safety practice for all mariners,
as uncorrected charts may contain hazards that have shifted position or aids that have been
discontinued.
Question 6 of 50
You are navigating through the Florida Keys using NOAA Chart 11451 and observe a sounding
of "04" with a subscript "s" located near a coral reef area. The tide is currently at mean high
water and your vessel draws 5.5 feet. You need to evaluate whether this area is safe for passage.
A. The "s" indicates a soft mud bottom where your keel will sink in safely without damage,
permitting passage at this tide stage.
B. The "s" denotes a sounding obtained by wire drag survey, meaning the depth may be less than
charted due to uncharted coral heads rising above the general bottom. ✓ CORRECT
ASA 105 Coastal Navigation Exam V2 Actual
Exam 2026/2027 | Complete Exam-Style
Questions | 100% Verified – Detailed
Rationales – Pass Guaranteed – A+ Graded
TABLE OF CONTENTS
Section 1 | Nautical Charts and Publications | Q1 – Q13
Section 2 | Plotting and Dead Reckoning | Q14 – Q25
Section 3 | Tides, Currents, and Weather | Q26 – Q37
Section 4 | Navigation Instruments and Electronic Navigation | Q38 – Q50
═══════════════════════════════════════════════════════
════════════
SECTION 1: NAUTICAL CHARTS AND PUBLICATIONS
═══════════════════════════════════════════════════════
════════════
Question 1 of 50
Your vessel is approaching the entrance to Chesapeake Bay from the Atlantic Ocean at 0800 on a
clear morning. You are using NOAA Chart 12221 and notice a magenta dashed line running
parallel to the entrance channel with the label "Safety Contour 18 ft." You need to determine the
minimum depth you can expect when crossing this contour line on a falling tide, given that the
charted depth in the adjacent channel is 22 feet and the tide range is 3.5 feet.
A. The safety contour indicates a dredged channel maintained at exactly 18 feet at all tidal
stages.
B. The safety contour marks the boundary where depths are less than 18 feet at the lowest
astronomical tide, so actual depth may vary.
C. The safety contour represents the 18-foot depth line at mean lower low water, providing a
conservative reference for safe passage. ✓ CORRECT
D. The safety contour is a historical reference only and does not reflect current survey data for
navigation purposes.
Correct Answer: C
,2
Rationale: The safety contour on modern NOAA charts is referenced to the chart datum, which
for the U.S. East Coast is typically mean lower low water (MLLW), meaning the 18-foot contour
indicates areas where 18 feet of depth can be expected at or below that tidal datum. Option A is
incorrect because safety contours are not guarantees of maintained dredged depth but rather
hydrographic representations based on soundings reduced to chart datum. Mariners should
always verify that their vessel's draft plus required under-keel clearance does not exceed the
available depth after accounting for tide height above chart datum.
Question 2 of 50
While planning a coastal passage from Newport, Rhode Island to Block Island, you consult
NOAA Chart 13209 and the accompanying Coast Pilot. You observe a symbol on the chart
depicting a black square with a dot in the center located on a prominent headland. You need to
identify this aid to navigation and determine its primary purpose for your daylight approach.
A. It indicates a lighted buoy with a horn sounding every 30 seconds for fog navigation.
B. It represents a daybeacon with no lateral significance, used to mark a specific navigational
feature or hazard. ✓ CORRECT
C. It denotes a radar reflector installed on an uncharted obstruction for electronic navigation.
D. It signifies a temporary floating mark placed by local fishermen to indicate lobster trap
locations.
Correct Answer: B
Rationale: A black square with a central dot is the standard chart symbol for a daybeacon, which
is an unlighted fixed aid to navigation typically used to mark hazards, channels, or specific
geographic features without conveying lateral channel significance. Option A is tempting
because many aids have lights, but the symbol specifically lacks the magenta flare or light
characteristic notation that would indicate a lighted aid. Daybeacons are essential reference
points for visual piloting, particularly when cross-bearing with other fixed objects to confirm
vessel position near rocky coastlines.
Question 3 of 50
You are preparing for a voyage from San Francisco Bay to Monterey Bay and are reviewing the
chart catalog to select appropriate paper charts. You note that NOAA Chart 18680 covers the
entire route at a scale of 1:200,000, while Chart 18685 covers only the approach to Monterey
Harbor at 1:40,000. You need to determine which chart would provide the most detailed depth
soundings and shoreline features for the final harbor approach.
A. Chart 18685 at 1:40,000 will display significantly greater detail including individual rocks,
small-craft anchorages, and precise depth curves. ✓ CORRECT
,3
B. Chart 18680 at 1:200,000 is superior for harbor approach because larger scale charts always
show more navigational detail.
C. Both charts contain identical sounding data because NOAA uses the same survey resolution
for all coastal charts regardless of scale.
D. Chart 18680 should be used exclusively because it covers the entire route, eliminating the
need to switch charts during the passage.
Correct Answer: A
Rationale: Nautical chart scale is expressed as a ratio where a smaller denominator indicates a
larger scale chart; thus 1:40,000 is a larger scale than 1:200,000 and will show more detailed
soundings, smaller geographic features, and precise navigation aids in the harbor approach.
Option B confuses the terminology—mariners often mistakenly believe "larger scale" means a
bigger number, when in fact it means a smaller ratio denominator representing more detail per
unit area. Always transition to the largest scale chart available when making a harbor approach to
ensure you can identify all hazards and navigation marks.
Question 4 of 50
While transiting the Intracoastal Waterway near St. Augustine, Florida, you encounter a junction
buoy marked on NOAA Chart 11485 with a horizontal band of red and green. Your vessel is
proceeding southbound in the waterway and must determine the proper course of action when
approaching this aid from the north.
A. Keep the buoy to starboard regardless of direction of travel because red marks the right side
of the channel.
B. Pass close aboard to port because green always indicates the edge of safe water on your port
side.
C. Alter course to avoid the mark entirely, as junction buoys indicate submerged wrecks and
should never be approached.
D. Treat the buoy as a preferred channel mark where the top color indicates the preferred channel
for your direction of travel. ✓ CORRECT
Correct Answer: D
Rationale: A junction buoy with horizontal red and green bands is a preferred channel mark
where the top band indicates the preferred channel; when proceeding southbound, the top color
determines whether you leave it to port or starboard based on the "red right returning"
convention applied to the preferred channel. Option A is incorrect because it ignores the dual-
color nature of the mark and the fact that the top color governs the preferred channel indication,
not simply the presence of red. Junction buoys require careful observation from a distance to
, 4
correctly identify the top color, as misidentification in poor visibility can lead to grounding on a
shoal at the channel intersection.
Question 5 of 50
Your vessel is anchored in Puget Sound and you are reviewing the Local Notice to Mariners to
check for chart corrections published within the last month. You find an entry stating "Chart
18441, permanent change, reposition lighted buoy PG '3' to 47°43.2'N, 122°31.8'W." You need to
apply this correction to your paper chart using the standard method prescribed by NOAA.
A. Use a pencil to lightly mark the new position and note the correction date in the chart title
block.
B. Apply correction fluid to remove the old buoy position, then ink in the new location and erase
the fluid after drying.
C. Use a fine-point permanent pen to ink in the new buoy position, draw a connecting line from
the old position if nearby, and record the Notice number and date in the lower left margin. ✓
CORRECT
D. Write the correction details only in the vessel's logbook, as chart corrections should never be
marked directly on the chart.
Correct Answer: C
Rationale: Standard NOAA protocol requires that permanent chart corrections be applied in
permanent ink to ensure they are not accidentally erased, with the correction source documented
in the chart margin to maintain traceability and indicate when the chart was last updated. Option
A is incorrect because pencil marks can be erased by moisture or handling, potentially leaving
the navigator with outdated information during a critical passage. Maintaining properly corrected
charts is a legal requirement for commercial vessels and a critical safety practice for all mariners,
as uncorrected charts may contain hazards that have shifted position or aids that have been
discontinued.
Question 6 of 50
You are navigating through the Florida Keys using NOAA Chart 11451 and observe a sounding
of "04" with a subscript "s" located near a coral reef area. The tide is currently at mean high
water and your vessel draws 5.5 feet. You need to evaluate whether this area is safe for passage.
A. The "s" indicates a soft mud bottom where your keel will sink in safely without damage,
permitting passage at this tide stage.
B. The "s" denotes a sounding obtained by wire drag survey, meaning the depth may be less than
charted due to uncharted coral heads rising above the general bottom. ✓ CORRECT
