ASA 105 Coastal Navigation Exam V2
ACTUAL EXAM 2026/2027 | ASA 105
Navigation V2 | Verified Q&A | Pass
Guaranteed - A+ Graded
Section 1: Nautical Charts & Publications (Questions 1–15)
Q1: On a NOAA nautical chart, a magenta dashed line with the label "DW" indicates:
A. Deep water channel with minimum depth of 20 feet
B. Dredged channel with controlling depth shown in feet [CORRECT]
C. Dangerous waters – avoid this area
D. Distant water boundary for territorial limits
Correct Answer: B
Rationale: NOAA charts use magenta dashed lines with "DW" to denote dredged channels, and the
controlling depth is expressed in feet at mean lower low water (MLLW). This is a standard chart symbol
indicating maintained channel depth for safe navigation.
Q2: A chart with a scale of 1:80,000 is classified as:
A. Harbor chart – suitable for detailed anchorage planning
B. General chart – used for offshore passage planning
C. Coastal chart – appropriate for inshore navigation and coastal cruising [CORRECT]
D. Sailing chart – used for transoceanic voyages
Correct Answer: C
Rationale: Coastal charts typically have scales between 1:50,000 and 1:150,000, making them ideal for
inshore navigation where detail and area coverage are balanced. Harbor charts are larger scale
(1:10,000 to 1:50,000), while general charts are smaller scale (1:150,000 to 1:600,000).
Q3: On a NOAA chart, soundings shown in italic typeface with a smaller font size indicate:
,A. Soundings in fathoms
B. Soundings in meters
C. Soundings from a partial or doubtful survey [CORRECT]
D. Soundings that represent dredged depths
Correct Answer: C
Rationale: NOAA chart conventions specify that italicized, smaller soundings indicate data from partial,
doubtful, or old surveys where the hydrographic data may be less reliable. Standard soundings are
shown in upright typeface.
Q4: The chart datum for soundings on U.S. coastal charts is:
A. Mean sea level (MSL)
B. Mean high water (MHW)
C. Mean lower low water (MLLW) [CORRECT]
D. Lowest astronomical tide (LAT)
Correct Answer: C
Rationale: U.S. NOAA charts use Mean Lower Low Water (MLLW) as the chart datum for soundings. This
is the average of the lower of the two daily low tides over a 19-year tidal epoch, providing a
conservative reference for minimum water depths.
Q5: A charted depth of 18 feet at MLLW with a tide height of +8.5 feet above MLLW means the actual
water depth is:
A. 9.5 feet
B. 18 feet
C. 26.5 feet [CORRECT]
D. 26.5 meters
Correct Answer: C
Rationale: Actual water depth equals charted depth plus the height of tide above chart datum.
Therefore, 18 feet + 8.5 feet = 26.5 feet. This calculation is fundamental for determining safe under-keel
clearance.
,Q6: The compass rose on a NOAA chart shows an inner ring labeled "MAG" and an outer ring labeled
"TRUE." If the variation printed is 14°30'W (2020), with an annual increase of 8', what is the variation in
2026?
A. 14°30'W
B. 15°18'W [CORRECT]
C. 15°30'W
D. 14°18'W
Correct Answer: B
Rationale: From 2020 to 2026 is 6 years. At 8 minutes increase per year: 6 × 8' = 48' = 0°48'. Adding to
the 2020 value: 14°30'W + 0°48' = 15°18'W. Annual change rates are printed on the compass rose for
this exact calculation.
Q7: A "Notice to Mariners" is published:
A. Only when major chart corrections are required
B. Weekly by the National Geospatial-Intelligence Agency and District Coast Guard offices [CORRECT]
C. Monthly in the Federal Register
D. Quarterly as part of the Light List updates
Correct Answer: B
Rationale: The U.S. Coast Guard and National Geospatial-Intelligence Agency publish weekly Notices to
Mariners containing critical chart corrections, light list updates, and safety information. Mariners are
responsible for applying these corrections to maintain chart accuracy.
Q8: On a chart, a black square with a dot in the center represents:
A. A submerged wreck
B. A visible wreck
C. A rock awash at chart datum
D. A position reported but not thoroughly surveyed [CORRECT]
Correct Answer: D
Rationale: A black square with a central dot is the standard NOAA chart symbol for a position (such as a
sounding, obstruction, or feature) that has been reported but not thoroughly surveyed or verified. This
warns navigators of potential inaccuracy.
, Q9: The "Coast Pilot" publication provides information about:
A. Only harbor facilities and marina services
B. Sailing directions, navigational regulations, and local conditions not shown on charts [CORRECT]
C. Real-time weather forecasts and sea state analysis
D. International maritime law and collision regulations
Correct Answer: B
Rationale: The NOAA Coast Pilot (volumes 1–9 for U.S. waters) supplements nautical charts with detailed
sailing directions, port information, local regulations, currents, weather patterns, and hazards that
cannot be fully depicted on charts alone.
Q10: Charted depths are given in feet on U.S. charts. One fathom equals:
A. 3 feet
B. 5 feet
C. 6 feet [CORRECT]
D. 10 feet
Correct Answer: C
Rationale: A fathom is a nautical unit of depth equal to 6 feet. Some older or specialized charts may
express soundings in fathoms, requiring conversion to feet for depth calculations relevant to vessel
draft.
Q11: A green shaded area on a NOAA chart with intermittent blue lines indicates:
A. A military exercise area
B. A marsh or wetland area [CORRECT]
C. A recommended anchorage zone
D. A dredge spoil disposal site
Correct Answer: B
Rationale: Green shaded areas with blue line patterns represent marsh, wetland, or swamp areas on
NOAA charts. These are intertidal zones that may be navigable only at high tide and require local
knowledge for safe passage.
Q12: The "Light List" publication contains:
ACTUAL EXAM 2026/2027 | ASA 105
Navigation V2 | Verified Q&A | Pass
Guaranteed - A+ Graded
Section 1: Nautical Charts & Publications (Questions 1–15)
Q1: On a NOAA nautical chart, a magenta dashed line with the label "DW" indicates:
A. Deep water channel with minimum depth of 20 feet
B. Dredged channel with controlling depth shown in feet [CORRECT]
C. Dangerous waters – avoid this area
D. Distant water boundary for territorial limits
Correct Answer: B
Rationale: NOAA charts use magenta dashed lines with "DW" to denote dredged channels, and the
controlling depth is expressed in feet at mean lower low water (MLLW). This is a standard chart symbol
indicating maintained channel depth for safe navigation.
Q2: A chart with a scale of 1:80,000 is classified as:
A. Harbor chart – suitable for detailed anchorage planning
B. General chart – used for offshore passage planning
C. Coastal chart – appropriate for inshore navigation and coastal cruising [CORRECT]
D. Sailing chart – used for transoceanic voyages
Correct Answer: C
Rationale: Coastal charts typically have scales between 1:50,000 and 1:150,000, making them ideal for
inshore navigation where detail and area coverage are balanced. Harbor charts are larger scale
(1:10,000 to 1:50,000), while general charts are smaller scale (1:150,000 to 1:600,000).
Q3: On a NOAA chart, soundings shown in italic typeface with a smaller font size indicate:
,A. Soundings in fathoms
B. Soundings in meters
C. Soundings from a partial or doubtful survey [CORRECT]
D. Soundings that represent dredged depths
Correct Answer: C
Rationale: NOAA chart conventions specify that italicized, smaller soundings indicate data from partial,
doubtful, or old surveys where the hydrographic data may be less reliable. Standard soundings are
shown in upright typeface.
Q4: The chart datum for soundings on U.S. coastal charts is:
A. Mean sea level (MSL)
B. Mean high water (MHW)
C. Mean lower low water (MLLW) [CORRECT]
D. Lowest astronomical tide (LAT)
Correct Answer: C
Rationale: U.S. NOAA charts use Mean Lower Low Water (MLLW) as the chart datum for soundings. This
is the average of the lower of the two daily low tides over a 19-year tidal epoch, providing a
conservative reference for minimum water depths.
Q5: A charted depth of 18 feet at MLLW with a tide height of +8.5 feet above MLLW means the actual
water depth is:
A. 9.5 feet
B. 18 feet
C. 26.5 feet [CORRECT]
D. 26.5 meters
Correct Answer: C
Rationale: Actual water depth equals charted depth plus the height of tide above chart datum.
Therefore, 18 feet + 8.5 feet = 26.5 feet. This calculation is fundamental for determining safe under-keel
clearance.
,Q6: The compass rose on a NOAA chart shows an inner ring labeled "MAG" and an outer ring labeled
"TRUE." If the variation printed is 14°30'W (2020), with an annual increase of 8', what is the variation in
2026?
A. 14°30'W
B. 15°18'W [CORRECT]
C. 15°30'W
D. 14°18'W
Correct Answer: B
Rationale: From 2020 to 2026 is 6 years. At 8 minutes increase per year: 6 × 8' = 48' = 0°48'. Adding to
the 2020 value: 14°30'W + 0°48' = 15°18'W. Annual change rates are printed on the compass rose for
this exact calculation.
Q7: A "Notice to Mariners" is published:
A. Only when major chart corrections are required
B. Weekly by the National Geospatial-Intelligence Agency and District Coast Guard offices [CORRECT]
C. Monthly in the Federal Register
D. Quarterly as part of the Light List updates
Correct Answer: B
Rationale: The U.S. Coast Guard and National Geospatial-Intelligence Agency publish weekly Notices to
Mariners containing critical chart corrections, light list updates, and safety information. Mariners are
responsible for applying these corrections to maintain chart accuracy.
Q8: On a chart, a black square with a dot in the center represents:
A. A submerged wreck
B. A visible wreck
C. A rock awash at chart datum
D. A position reported but not thoroughly surveyed [CORRECT]
Correct Answer: D
Rationale: A black square with a central dot is the standard NOAA chart symbol for a position (such as a
sounding, obstruction, or feature) that has been reported but not thoroughly surveyed or verified. This
warns navigators of potential inaccuracy.
, Q9: The "Coast Pilot" publication provides information about:
A. Only harbor facilities and marina services
B. Sailing directions, navigational regulations, and local conditions not shown on charts [CORRECT]
C. Real-time weather forecasts and sea state analysis
D. International maritime law and collision regulations
Correct Answer: B
Rationale: The NOAA Coast Pilot (volumes 1–9 for U.S. waters) supplements nautical charts with detailed
sailing directions, port information, local regulations, currents, weather patterns, and hazards that
cannot be fully depicted on charts alone.
Q10: Charted depths are given in feet on U.S. charts. One fathom equals:
A. 3 feet
B. 5 feet
C. 6 feet [CORRECT]
D. 10 feet
Correct Answer: C
Rationale: A fathom is a nautical unit of depth equal to 6 feet. Some older or specialized charts may
express soundings in fathoms, requiring conversion to feet for depth calculations relevant to vessel
draft.
Q11: A green shaded area on a NOAA chart with intermittent blue lines indicates:
A. A military exercise area
B. A marsh or wetland area [CORRECT]
C. A recommended anchorage zone
D. A dredge spoil disposal site
Correct Answer: B
Rationale: Green shaded areas with blue line patterns represent marsh, wetland, or swamp areas on
NOAA charts. These are intertidal zones that may be navigable only at high tide and require local
knowledge for safe passage.
Q12: The "Light List" publication contains:
