USCG General Navigation: Master's License

This is an interactive test. Read each question and select the proper answer by clicking on the appropriate answer. If a "Y" appears, your choice is correct. If a "N" appears, more study may be in order.


3: Blinking of a Loran-C signal indicates __________.


27: Spring tides are tides that __________.


102: Which statement about an NGA (NIMA) chart with stock no.23BHA23433 is TRUE?


170: Which of the buoy symbols in illustration D032NG indicates a safe water mark?

    Y a. D
    N b. C
    N c. B
    N d. A

264: Which of the four adjustable errors in the sextant is the principle cause of index error?

    N a. Telescope not being parallel to the frame
    Y b. Index mirror and horizon glass not being parallel
    N c. Index mirror not being perpendicular to the frame
    N d. Horizon glass not being perpendicular to the frame

280: Under the U.S. Aids to Navigation System, a lighted buoy with a spherical topmark marks __________.

    N a. the port side of the channel
    Y b. safe water
    N c. a hazard to navigation
    N d. the position of underwater cables

312: The depth of water on a chart is indicated as 23 meters. This is equal to __________.

    N a. 11.5 fathoms
    Y b. 12.6 fathoms
    N c. 69.0 feet
    N d. 78.6 feet

372: You would find the variation on a polyconic projection chart __________.

    Y a. on the compass rose
    N b. on the mileage scale
    N c. written on the chart title
    N d. at each line of longitude

407: What would be the height of the tide at Crisfield, MD, at 0310 DST (ZD +4) on 6 May 1983?

    N a. 0.1 foot
    Y b. 0.5 foot
    N c. 1.1 feet
    N d. 1.6 feet

440: You are inbound in a channel marked by a range. The range line is 309°T. You are steering 306°T. The range appears as shown and is closing. Which action should you take? (D047NG )

    N a. Continue on the present heading until the range is in line, then alter course to the left.
    N b. Immediately alter course to the right to bring the range in line.
    N c. Immediately alter course to 309°T.
    Y d. Continue on course until the range is closed, then alter course to the right.

518: With regard to GPS, a civilian receiver may be capable of achieving the same accuracy as a military receiver if __________.

    Y a. selective availability is set to zero
    N b. the satellites are all below 15° in elevation
    N c. your vessel is equipped with a Doppler receiver
    N d. the horizontal dilution of precision is high

575: The horizontal plane, perpendicular to the zenith-nadir axis, that intersects with the celestial sphere and is tangent to the earth is called the __________.

    N a. celestial horizon
    N b. sensible horizon
    N c. visible horizon
    Y d. geoidal horizon

588: You are underway on course 050°T and your maximum speed is 10 knots. The eye of a hurricane bears 100°T, 90 miles from your position. The hurricane is moving towards 285°T at 19 knots. If you maneuver at 10 knots to avoid the hurricane, what could be the maximum CPA?

    N a. 39 miles
    N b. 45 miles
    Y c. 53 miles
    N d. 59 miles

600: The dangerous semicircle of a typhoon in the Southern Hemisphere is that area __________.

    N a. measured from due south clockwise 180°
    N b. measured from due south counterclockwise 180°
    Y c. to the left of the storm's track
    N d. ahead of the typhoon measured from the storm's track to 90° on each side

705: The precession of the equinoxes occurs in a(n) __________.

    N a. easterly direction
    Y b. westerly direction
    N c. northerly direction
    N d. southerly direction

802: Which is a weekly publication advising mariners of important matters affecting navigational safety?

    N a. Light List
    Y b. Notice to Mariners
    N c. Coast Pilot
    N d. Sailing Directions

834: In many areas "atoll" clouds (clouds of vertical development) are produced over small islands. These are the result of __________.

    Y a. rising air currents produced by the warm islands
    N b. warm air from the sea rising over higher land areas
    N c. cool land air mixing with warm sea air
    N d. descending air over the islands

959: What is the index error of sextant B in illustration D050NG? (D050NG )

    N a. 0'30" off the arc
    N b. 1'00" off the arc
    Y c. 3'30" off the arc
    N d. 1'30" on the arc

1004: A low, uniform layer of cloud resembling fog, but not resting on the ground, is called __________.

    N a. cumulus
    N b. nimbus
    Y c. stratus
    N d. cirrus

1067: The two most effective generating forces of surface ocean currents are __________.

    N a. temperature and salinity differences in the water
    Y b. wind and density differences in the water
    N c. water depth and underwater topography
    N d. rotation of the Earth and continental interference

1119: The position labeled "D" was plotted because __________. (D051NG )

    N a. the vessel's speed changed at 1125
    N b. a dead reckoning position is plotted within 30 minutes of a running fix
    Y c. a dead reckoning position is plotted for each course change
    N d. All of the above

1146: What is true about a front?

    N a. A front is a boundary between two air masses.
    N b. There are abrupt temperature differences on opposite sides of a front.
    N c. The pressure tendencies are different on opposite sides of a front.
    Y d. All of the above

1184: Your position X is at LAT 35°S. Which winds are you experiencing? (D009NG )

    Y a. Northeasterly
    N b. Northwesterly
    N c. Southeasterly
    N d. Southwesterly

1263: The compass deviation changes as the vessel changes __________.

    N a. geographical position
    N b. speed
    Y c. heading
    N d. longitude

1291: The period of a lighted aid to navigation refers to the __________.

    N a. date of construction or establishment
    N b. length of time between flashes of the light
    N c. time required for the longest flash of each cycle
    Y d. time required for the light to complete each cycle

1307: What will be the velocity of the tidal current southwest of Hunts Point, NY, at 0932 EST (ZD +5) on 16 March 1983?

    N a. 0.9 knot
    Y b. 1.5 knots
    N c. 1.8 knots
    N d. 2.3 knots

1333: If a magnetic compass is not affected by any magnetic field other than the Earth's, which statement is TRUE?

    Y a. Compass error and variation are equal.
    N b. Compass north will be true north.
    N c. Variation will equal deviation.
    N d. There will be no compass error.

1377: What is the velocity of the tidal current at the east end of Pollock Rip Channel at 1700 DST (ZD +4) on 23 July 1983?

    N a. 0.6 knot ebbing
    N b. 0.8 knot flooding
    Y c. 1.5 knots flooding
    N d. 1.9 knots flooding

1400: Which type of cloud is among the most dependable for giving an indication of an approaching weather system?

    N a. Cumulus
    Y b. Altostratus
    N c. Cumulostratus
    N d. Nimbus

1432: What benefit is a weather bulletin to a mariner?

    N a. It provides a legal reason to cancel a projected voyage.
    N b. It allows the mariner to make long term weather forecasts.
    N c. It is of little benefit since the weather changes frequently and rapidly.
    Y d. It gives the mariner time to prepare for weather changes.

1438: In the Northern Hemisphere you are caught in the dangerous semicircle of a storm with plenty of sea room available. The best course of action is to bring the wind on the __________.

    N a. port quarter and make as much headway as possible
    N b. starboard quarter and make as much headway as possible
    Y c. starboard bow and make as much headway as possible
    N d. port bow and make as much headway as possible

1493: You are running parallel to the coast and estimate that the current is against you. In plotting a running fix using bearings from the same object on the coast, the greatest safety margin from inshore dangers will result if what speed is used to determine the fix?

    Y a. Minimum speed estimate
    N b. Maximum speed estimate
    N c. Average speed estimate
    N d. A running fix should not be used under these conditions.

1564: What is a characteristic of cardinal marks?

    Y a. Light rhythms indicating directional orientation
    N b. Vertical stripes
    N c. Square or triangular topmarks
    N d. Number-letter combinations for identification

1615: The Illustration shows the symbols used on radio facsimile weather charts. Which symbol indicates snow? (D042NG )

    N a. G
    N b. H
    Y c. M
    N d. N

1690: In regions near the poles, the winds are generally described as __________.

    N a. westerlies
    Y b. easterlies
    N c. northerlies
    N d. southerlies

1734: The eye of the hurricane has __________.

    N a. very high barometric pressure
    N b. average barometric pressure
    Y c. the lowest barometric pressure
    N d. no change in barometric pressure

1743: In the Northern Hemisphere, if your vessel is in a hurricane's navigable semicircle it should be positioned with the wind on the __________.

    Y a. starboard quarter, hold course and make as much speed as possible
    N b. port bow, hold course and make as much speed as possible until the hurricane has passed
    N c. port quarter, maintain course and make as much speed as possible
    N d. starboard bow and heave to until the hurricane has passed

1882: The GP of a body for a high altitude sight is determined from the Greenwich hour angle and the __________.

    N a. circle of equal altitude
    N b. zenith distance
    N c. azimuth angle
    Y d. declination

1955: The letter A in illustration D006NG represents the __________.

    N a. geoidal horizon
    Y b. sensible horizon
    N c. celestial horizon
    N d. visible horizon

1969: The precession of the equinoxes of the Earth is __________.

    N a. the gradual increase in the period of rotation caused by the effects of the Moon
    N b. the irregularity of the Earth's orbit caused by influences of the Sun and Moon
    N c. caused by the elliptical shape of the Earth's orbit
    Y d. similar to a top spinning with its axis tilted

2220: A dead reckoning (DR) plot __________.

    N a. must utilize magnetic courses
    N b. must take set and drift into account
    N c. should be replotted hourly
    Y d. should be started each time the vessel's position is fixed

2312: Mars is only seen at two phases, one of which __________.

    Y a. is the full phase
    N b. is conjunction
    N c. occurs only at sunset or sunrise
    N d. occurs at or near 0° elongation

2350: The principal advantage of NAVTEX radio warnings is that __________.

    Y a. they can be used by mariners who do not know Morse code
    N b. only an ordinary FM radio is necessary to receive these warnings
    N c. information on a given topic is only broadcast at specified times
    N d. they cover a broad spectrum of the radio band allowing reception on almost any type of receiver

2360: What U.S. agency is responsible for NAVAREA warnings?

    N a. Coast Guard
    N b. National Oceanic and Atmospheric Administration
    N c. National Ocean Service
    Y d. National Geospatial-Intelligence Agency

2435: What is a lighted safe water mark fitted with to aid in its identification?

    N a. A red and white octagon
    N b. Red and white retroreflective material
    N c. A sequential number
    Y d. A spherical topmark

2454: Illustration D037NG represents a moveable dam. If the wickets are down and there are open weirs due to high water, what light(s) will be shown at C if the lock walls and piers are not awash? (D037NG )

    N a. One red light
    Y b. Two red lights
    N c. Three red lights
    N d. One amber light

2589: Under the IALA cardinal system, a mark with a quick white light showing 6 flashes followed by one long flash indicates that the safest water is on the __________.

    N a. north side of the mark
    N b. west side of the mark
    N c. east side of the mark
    Y d. south side of the mark

2672: When you are steering on a pair of range lights and find the upper light is in line above the lower light, you should __________.

    Y a. continue on the present course
    N b. come left
    N c. come right
    N d. wait until the lights are no longer in a vertical line

2696: You must draw a plotting sheet covering latitudes 52°S to 56°S and longitudes 179°W to 175°E. If the distance between latitude 52°S to 56°S is 24 inches, what is the distance between the meridians of 1° of longitude?

    N a. 3.2 inches
    Y b. 3.5 inches
    N c. 4.0 inches
    N d. 4.2 inches

2726: A daymark used as a special mark is indicated by which letter in the diagram? (D045NG )

    N a. A
    Y b. B
    N c. C
    N d. D

2762: You take a bearing of 176° of a lighthouse. Which bearing of another object would give the best fix?

    Y a. 079°
    N b. 151°
    N c. 176°
    N d. 292°

2770: What is most likely to happen when you push a multiple tow into a countercurrent?

    N a. Going upstream you will make better speed with no danger involved.
    N b. Going downstream you will be slowed down but will keep control of the tow.
    Y c. There is a good chance you will break up the tow.
    N d. No danger exists as long as you steer a straight course through the eddy.

2809: The diurnal variation of pressure is not visible in the middle latitudes in winter because __________.

    Y a. it is masked by the pressure changes of moving weather systems
    N b. the decreased gravitational effect from the sun causes the variation to fade
    N c. the decreased average temperature is less than the critical temperature
    N d. the increased Coriolis force disperses the pressure variation

2850: What is used to help prevent damage to barges, locks, and landings when you are locking or landing a tow?

    N a. Dock cushions
    N b. Springers
    N c. Landing bars
    Y d. Bumpers (fenders)

2884: The pictures shown represent the geographic location of a vessel and the radar presentation at the same time. Which statement is TRUE? (D011NG )

    Y a. Ship No. 1 does not appear as an individual target due to the effect of beam width.
    N b. Small island is not detected due to the multiple echo effect from the mountain.
    N c. A tangent bearing of the headland to the south-southeast is corrected by subtracting one-half of the beam width.
    N d. Ship No. 2 is not detected due to the side lobe effect of radar reflecting from the mountain.

2931: The vertical distance from the tidal datum to the level of the water is the __________.

    N a. range of tide
    Y b. height of tide
    N c. actual water depth
    N d. charted depth

3017: A rotary current sets through all directions of the compass. The time it takes to complete one of these cycles, in a locale off the East coast of the US, is approximately __________.

    N a. 3 hours
    N b. 6 1/4 hours
    Y c. 12 1/2 hours
    N d. 18 3/4 hours

3022: A green-and-red banded daymark, green band uppermost, will have the shape shown at letter __________. (D045NG )

    Y a. A
    N b. B
    N c. C
    N d. D

3056: A position obtained by applying ONLY your vessel's course and speed to a known position is a __________.

    N a. fix
    Y b. dead-reckoning position
    N c. running fix
    N d. probable position

3070: The database information that should be shown when a chart is first displayed on ECDIS is the __________.

    N a. display base information
    Y b. standard display information
    N c. system electronic nautical chart
    N d. chart display information