ASA 105 EXAM V1 2026/2027 | Coastal Navigation
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Graded
SECTION 1: NAUTICAL CHARTS & CHART PROJECTIONS (20
Questions)
Q1: A navigator measures a distance on a Mercator chart using the latitude scale. One
minute of latitude equals:
A. 1 statute mile
B. 1 kilometer
C. 1 nautical mile [CORRECT]
D. 1 meter
Correct Answer: C
Rationale: On all Mercator charts, one minute of latitude (1') equals one nautical mile
(approximately 6,076 feet or 1,852 meters) regardless of location. This is why distances
are always measured using the latitude scale, not the longitude scale, as longitude
distances vary with latitude due to Mercator projection distortion.
Q2: On a Mercator projection, a straight line drawn between two points represents:
A. A great circle route
B. A rhumb line (loxodrome) [CORRECT]
C. The shortest distance between the points
D. A line of constant longitude
Correct Answer: B
Rationale: On a Mercator chart, straight lines are rhumb lines that cross all meridians at
the same angle, making them easy to steer with a constant compass course. Great
circle routes (the shortest distance between two points) appear as curves on Mercator
projections except when following a meridian or the equator.
Q3: A chart with a scale of 1:20,000 is considered:
,A. A small-scale chart for offshore navigation
B. A large-scale chart for harbor and approach navigation [CORRECT]
C. A general chart for coastal cruising
D. A sailing chart for ocean passages
Correct Answer: B
Rationale: Large-scale charts (1:20,000 to 1:50,000) show small areas with great detail
and are used for harbors, anchorages, and approaches. Small-scale charts (1:150,000 or
smaller) cover larger areas with less detail for offshore and coastal navigation. The
larger the ratio denominator, the smaller the scale.
Q4: The navigator consults U.S. Chart No. 1 to identify:
A. Tide predictions for local harbors
B. Standard chart symbols, abbreviations, and terms [CORRECT]
C. Magnetic variation for specific regions
D. VHF radio frequencies for coastal stations
Correct Answer: B
Rationale: Chart No. 1 is the standard reference publication that defines all symbols,
abbreviations, and terms used on nautical charts, including bottom types, navigational
aids, depth contours, and restricted areas. Tide predictions are found in Tide Tables,
variation in the compass rose, and VHF frequencies in the Coast Guard Light List or
Coast Pilot.
Q5: A depth sounding on a chart is followed by the abbreviation "(ft)". This indicates:
A. The depth is measured in fathoms
B. The depth is measured in feet [CORRECT]
C. The depth is measured in meters
D. The depth is a drying height above the datum
Correct Answer: B
Rationale: Charts indicate the unit of measurement for depth soundings: (ft) for feet,
(fm) for fathoms, or (m) for meters. Older U.S. charts often used fathoms or feet, while
modern charts and many foreign charts use meters. Drying heights are indicated
separately and show heights above chart datum exposed at low tide.
Q6: The horizontal datum of a modern electronic chart is most commonly:
,A. NAD27
B. WGS84 [CORRECT]
C. Local harbor datum
D. Mean sea level
Correct Answer: B
Rationale: WGS84 (World Geodetic System 1984) is the standard datum for GPS and
modern electronic navigation charts (ENCs), ensuring positional accuracy between
satellite fixes and charted features. Older paper charts may use NAD27 or NAD83, but
all modern systems have transitioned to WGS84 for compatibility.
Q7: A navigator must apply a correction from the Notice to Mariners because:
A. The chart's printing color has faded
B. A new aid to navigation has been established or an existing one has changed
[CORRECT]
C. The compass variation has changed annually
D. The chart scale needs adjustment
Correct Answer: B
Rationale: The Notice to Mariners provides weekly updates on changes to aids to
navigation, charted depths, bridge clearances, hazards, and other critical information
that occurs between chart editions. Mariners are legally required to keep charts
corrected to the latest Notice to Mariners for safe navigation.
Q8: On a nautical chart, a magenta dashed line with the label "Submarine Pipeline"
indicates:
A. A recommended sailing track
B. A submerged cable or pipeline that may be a hazard to anchoring [CORRECT]
C. A ferry route
D. A boundary between territorial waters
Correct Answer: B
Rationale: Submarine pipelines and cables are charted as hazards to anchoring and
fishing operations. The specific symbols and line patterns are defined in Chart No. 1.
Ferry routes typically have different symbols, and territorial boundaries are shown with
different line styles and colors.
, Q9: The compass rose on a nautical chart shows both inner and outer rings. The outer
ring indicates:
A. Magnetic directions referenced to magnetic north [CORRECT]
B. True directions referenced to true north
C. Compass directions corrected for deviation
D. Relative bearings from the vessel
Correct Answer: A
Rationale: The compass rose typically has an outer ring graduated in degrees relative to
true north (geographic north pole) and an inner ring showing magnetic north directions.
The variation between the two is printed in the center of the rose, along with the annual
rate of change and the year of measurement.
Q10: A "blue book" chart refers to:
A. A chart printed on waterproof paper
B. A chart printed by the National Ocean Service that has been corrected to the latest
Notice to Mariners [CORRECT]
C. A chart used exclusively for night navigation
D. A small-scale ocean planning chart
Correct Answer: B
Rationale: "Blue book" charts are charts printed by NOAA/NOS that include all
corrections from Notices to Mariners up to the print date. They are sold through
authorized chart agents and are distinct from print-on-demand charts or home-printed
copies that may lack recent corrections.
Q11: When measuring distance on a Mercator chart, the navigator should use:
A. The longitude scale at the equator
B. The latitude scale at the same latitude as the area being measured [CORRECT]
C. The compass rose diameter
D. The chart title block scale indicator only
Correct Answer: B
Rationale: Because the Mercator projection expands with latitude, the latitude scale
(vertical) is the only accurate measure of distance, and it should be used at the same
latitude as the area being measured for greatest accuracy. One minute of latitude
Certification Mastery | Verified Q&A | Pass Guaranteed - A+
Graded
SECTION 1: NAUTICAL CHARTS & CHART PROJECTIONS (20
Questions)
Q1: A navigator measures a distance on a Mercator chart using the latitude scale. One
minute of latitude equals:
A. 1 statute mile
B. 1 kilometer
C. 1 nautical mile [CORRECT]
D. 1 meter
Correct Answer: C
Rationale: On all Mercator charts, one minute of latitude (1') equals one nautical mile
(approximately 6,076 feet or 1,852 meters) regardless of location. This is why distances
are always measured using the latitude scale, not the longitude scale, as longitude
distances vary with latitude due to Mercator projection distortion.
Q2: On a Mercator projection, a straight line drawn between two points represents:
A. A great circle route
B. A rhumb line (loxodrome) [CORRECT]
C. The shortest distance between the points
D. A line of constant longitude
Correct Answer: B
Rationale: On a Mercator chart, straight lines are rhumb lines that cross all meridians at
the same angle, making them easy to steer with a constant compass course. Great
circle routes (the shortest distance between two points) appear as curves on Mercator
projections except when following a meridian or the equator.
Q3: A chart with a scale of 1:20,000 is considered:
,A. A small-scale chart for offshore navigation
B. A large-scale chart for harbor and approach navigation [CORRECT]
C. A general chart for coastal cruising
D. A sailing chart for ocean passages
Correct Answer: B
Rationale: Large-scale charts (1:20,000 to 1:50,000) show small areas with great detail
and are used for harbors, anchorages, and approaches. Small-scale charts (1:150,000 or
smaller) cover larger areas with less detail for offshore and coastal navigation. The
larger the ratio denominator, the smaller the scale.
Q4: The navigator consults U.S. Chart No. 1 to identify:
A. Tide predictions for local harbors
B. Standard chart symbols, abbreviations, and terms [CORRECT]
C. Magnetic variation for specific regions
D. VHF radio frequencies for coastal stations
Correct Answer: B
Rationale: Chart No. 1 is the standard reference publication that defines all symbols,
abbreviations, and terms used on nautical charts, including bottom types, navigational
aids, depth contours, and restricted areas. Tide predictions are found in Tide Tables,
variation in the compass rose, and VHF frequencies in the Coast Guard Light List or
Coast Pilot.
Q5: A depth sounding on a chart is followed by the abbreviation "(ft)". This indicates:
A. The depth is measured in fathoms
B. The depth is measured in feet [CORRECT]
C. The depth is measured in meters
D. The depth is a drying height above the datum
Correct Answer: B
Rationale: Charts indicate the unit of measurement for depth soundings: (ft) for feet,
(fm) for fathoms, or (m) for meters. Older U.S. charts often used fathoms or feet, while
modern charts and many foreign charts use meters. Drying heights are indicated
separately and show heights above chart datum exposed at low tide.
Q6: The horizontal datum of a modern electronic chart is most commonly:
,A. NAD27
B. WGS84 [CORRECT]
C. Local harbor datum
D. Mean sea level
Correct Answer: B
Rationale: WGS84 (World Geodetic System 1984) is the standard datum for GPS and
modern electronic navigation charts (ENCs), ensuring positional accuracy between
satellite fixes and charted features. Older paper charts may use NAD27 or NAD83, but
all modern systems have transitioned to WGS84 for compatibility.
Q7: A navigator must apply a correction from the Notice to Mariners because:
A. The chart's printing color has faded
B. A new aid to navigation has been established or an existing one has changed
[CORRECT]
C. The compass variation has changed annually
D. The chart scale needs adjustment
Correct Answer: B
Rationale: The Notice to Mariners provides weekly updates on changes to aids to
navigation, charted depths, bridge clearances, hazards, and other critical information
that occurs between chart editions. Mariners are legally required to keep charts
corrected to the latest Notice to Mariners for safe navigation.
Q8: On a nautical chart, a magenta dashed line with the label "Submarine Pipeline"
indicates:
A. A recommended sailing track
B. A submerged cable or pipeline that may be a hazard to anchoring [CORRECT]
C. A ferry route
D. A boundary between territorial waters
Correct Answer: B
Rationale: Submarine pipelines and cables are charted as hazards to anchoring and
fishing operations. The specific symbols and line patterns are defined in Chart No. 1.
Ferry routes typically have different symbols, and territorial boundaries are shown with
different line styles and colors.
, Q9: The compass rose on a nautical chart shows both inner and outer rings. The outer
ring indicates:
A. Magnetic directions referenced to magnetic north [CORRECT]
B. True directions referenced to true north
C. Compass directions corrected for deviation
D. Relative bearings from the vessel
Correct Answer: A
Rationale: The compass rose typically has an outer ring graduated in degrees relative to
true north (geographic north pole) and an inner ring showing magnetic north directions.
The variation between the two is printed in the center of the rose, along with the annual
rate of change and the year of measurement.
Q10: A "blue book" chart refers to:
A. A chart printed on waterproof paper
B. A chart printed by the National Ocean Service that has been corrected to the latest
Notice to Mariners [CORRECT]
C. A chart used exclusively for night navigation
D. A small-scale ocean planning chart
Correct Answer: B
Rationale: "Blue book" charts are charts printed by NOAA/NOS that include all
corrections from Notices to Mariners up to the print date. They are sold through
authorized chart agents and are distinct from print-on-demand charts or home-printed
copies that may lack recent corrections.
Q11: When measuring distance on a Mercator chart, the navigator should use:
A. The longitude scale at the equator
B. The latitude scale at the same latitude as the area being measured [CORRECT]
C. The compass rose diameter
D. The chart title block scale indicator only
Correct Answer: B
Rationale: Because the Mercator projection expands with latitude, the latitude scale
(vertical) is the only accurate measure of distance, and it should be used at the same
latitude as the area being measured for greatest accuracy. One minute of latitude
