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.


83: All Loran-C transmitting stations are equipped with cesium frequency standards which permit __________.


192: The description "Racon" beside an illustration on a chart would mean a __________.


269: The wind at Frying Pan shoals has been south-southwesterly at an average velocity of 30 knots. The predicted set and drift of the rotary current are 232° at 0.8 knot. What current should you expect?


344: A marine sextant has the index arm set at zero and the reflected image of the horizon forms a continuous line with the actual image. When the sextant is rotated about the line of sight the images separate. The sextant has __________.

    N a. error of perpendicularity
    Y b. side error
    N c. prismatic error
    N d. centering error

377: Determine the height of the tide at 2045 EST (ZD +5) at Augusta, ME, on 8 March 1983.

    N a. 1.4 feet (0.5 meter)
    Y b. 1.9 feet (0.6 meter)
    N c. 2.3 feet (0.7 meter)
    N d. 2.6 feet (0.8 meter)

427: On 23 March 1983, at Kingston Point, NY, what is the earliest time after 1700 EST (ZD +5) that the predicted tide will be +2.0 feet?

    N a. 1730
    N b. 1800
    Y c. 1854
    N d. 2030

430: The southeast trade winds actually blow toward the __________.

    N a. southeast
    N b. south
    N c. east
    Y d. northwest

434: The purpose of the "set" hand on an aneroid barometer is to __________.

    N a. adjust the barometer
    Y b. indicate any change in the reading of the barometer
    N c. provide a correction for height above sea level
    N d. provide a correction for temperature changes

474: Which indication on the barometer is most meaningful in forecasting weather?

    N a. The words "Fair -- Change -- Rain"
    Y b. The direction and rate of change of barometric pressure
    N c. The actual barometric pressure
    N d. The relative humidity

502: A gnomonic projection is based on a(n) __________.

    Y a. plane tangent at one point
    N b. cylinder tangent at the equator
    N c. cone tangent at one parallel
    N d. infinite series of cones tangent at selected parallels

519: The chart of a beach area shows a very flat slope to the underwater beach bottom. What type of breakers can be expected when trying to land a boat on this beach?

    N a. Surging
    Y b. Spilling
    N c. Plunging
    N d. Converging

520: On charts of U.S. waters, a magenta marking is NOT used for marking a __________.

    Y a. 5-fathom curve
    N b. prohibited area
    N c. lighted buoy
    N d. radio beacon

521: Which sextant has an index error of 2'10" on the arc? (D050NG )

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

547: On 2 November 1983, at 1630 EST (ZD +5), what will be the predicted height of tide at Fulton, FL?

    Y a. 2.8 feet (0.8 meters)
    N b. 3.4 feet (1.0 meters)
    N c. 4.2 feet (1.3 meters)
    N d. 5.6 feet (1.7 meters)

574: If your mercurial barometer reads 30.50 inches (1033 millibars) and the temperature is 56°F (13°C), what is the correct reading at 55°N, 150°W?

    N a. 30.42 inches (1030 millibars)
    Y b. 30.45 inches (1031 millibars)
    N c. 30.50 inches (1032 millibars)
    N d. 30.53 inches (1033 millibars)

592: To measure distance on a Mercator chart between the parallels of LAT 34°30'N and LAT 31°30'N, which 30 mile scale should be used?

    N a. 33°00'N to 33°30'N
    N b. 32°30'N to 33°00'N
    Y c. 32°45'N to 33°15'N
    N d. 32°15'N to 32°45'N

623: An indirect radar echo is caused by a reflection of the main lobe of the radar beam off the observer's vessel. Which of the following is NOT a characteristic of indirect echoes?

    N a. Their bearing is almost constant, even when the true bearing of the contact changes appreciably.
    Y b. They always appear on a bearing of 90°From the true bearing of the contact.
    N c. The indirect echoes usually appear in shadow sectors.
    N d. When plotted, their movements are usually abnormal.

683: A radar contact will remain stationary on a relative motion radar display only when it is __________.

    N a. on the same course as your vessel
    N b. at the same speed as your vessel
    Y c. on the same course and speed as your vessel
    N d. on a reciprocal course at the same speed as your vessel

759: At 0000 you fix your position and plot a new DR track line. At 0200 you again fix your position and it is 0.5 mile west of your DR. Which statement is TRUE?

    N a. The set is 090°, drift 0.5 knot.
    Y b. The set is 270°, drift 0.25 knot.
    N c. The set is 270°, drift 0.5 knot.
    N d. The set is 270°, drift 1.0 knot.

759: At 0000 you fix your position and plot a new DR track line. At 0200 you again fix your position and it is 0.5 mile west of your DR. Which statement is TRUE?

    N a. The set is 090°, drift 0.5 knot.
    Y b. The set is 270°, drift 0.25 knot.
    N c. The set is 270°, drift 0.5 knot.
    N d. The set is 270°, drift 1.0 knot.

785: An amplitude of the Sun in high latitudes __________.

    N a. is most accurate before sunrise
    N b. is most accurate after sunset
    N c. should only be observed when the Sun's lower limb is above the horizon
    Y d. is most accurate when the Sun's center is observed on the visible horizon

865: The radius of a circle of equal altitude of a body is equal to the __________.

    Y a. coaltitude of the body
    N b. altitude of the body
    N c. codeclination of the body
    N d. polar distance

878: At 0600 ZT on 31 January, your position is LAT 00°49'S, LONG 84°27'E. You are preparing a weather report form, WS Form B-80. How should you encode the first three groups after the call sign if you estimate the wind? (D041NG )

    N a. 30243, 90008, 30848
    N b. 31003, 99049, 38427
    Y c. 31003, 99008, 30844
    N d. 31063, 99049, 58427

965: In order for a star to be used for a sight at lower transit, the star must __________.

    Y a. be circumpolar
    N b. have a declination equal to or greater than your latitude
    N c. have a GHA of 180°
    N d. have the SHA equal to or less than the LHA

1042: What is the approximate geographic range of Shinnecock Light, NY, if your height of eye is 24 feet (7.3 meters)? Refer to "Reprints from the LIGHT LISTS AND COAST PILOTS" .

    N a. 8.7 nm
    N b. 9.9 nm
    N c. 14.4 nm
    Y d. 15.9 nm

1068: A vessel sighting a northern right whale dead ahead should __________.

    N a. maintain course and speed
    Y b. alter course to give a wide clearance
    N c. report the whale's position to the Canadian Coast Guard
    N d. All of the above

1074: As the temperature for a given mass of air increases, the __________.

    N a. dew point increases
    N b. dew point decreases
    N c. relative humidity increases
    Y d. relative humidity decreases

1075: The expression "first magnitude" is usually used to refer only to bodies of magnitude __________.

    Y a. 1.5 and greater
    N b. 1.25 and greater
    N c. 1.0 and greater
    N d. 0.5 and greater

1209: You are on course 201°T. To check the speed of your vessel you should observe a celestial body on which bearing?

    N a. 090°
    N b. 111°
    N c. 180°
    Y d. 201°

1221: On a chart, the characteristic of the light on a lighthouse is shown as flashing white with a red sector. The red sector __________.

    N a. indicates the limits of the navigable channel
    Y b. indicates a danger area
    N c. is used to identify the characteristics of the light
    N d. serves no significant purpose

1250: Daylight savings time is a form of zone time that adopts the time __________.

    Y a. one zone to the east
    N b. one zone to the west
    N c. two zones to the east
    N d. two zones to the west

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

1431: A lighthouse is 120 feet (36.6 meters) high and the light has a nominal range of 18 miles. Your height of eye is 42 feet (12.8). If the visibility is 11 miles, approximately how far off the light will you be when the light becomes visible?

    N a. 12.5 miles
    N b. 16.0 miles
    Y c. 19.0 miles
    N d. 23.5 miles

1444: Stratocumulus clouds are indicated by which number? (D039NG )

    N a. 1
    N b. 4
    Y c. 6
    N d. 7

1466: Advection fog is most commonly caused by __________.

    N a. air being warmed above the dew point
    N b. saturation of cold air by rain
    N c. a rapid cooling of the air near the surface of the Earth at night
    Y d. warm moist air being blown over a colder surface

1484: You should plot your dead reckoning position at __________.

    N a. every fix or running fix
    N b. every course change
    N c. every speed change
    Y d. All of the above are correct.

1712: Tornados are often associated with __________.

    N a. winds in the warm sector ahead of a cold front and travel from southwest towards the east or northeast
    N b. squall lines and very heavy thunderstorm activity
    N c. winds that may be in excess of 200 knots and destructive funnel clouds
    Y d. All of the above

1788: You can follow the approach of a dangerous cyclonic storm by inspecting __________.

    N a. the Coast Pilot or Sailing Directions
    N b. the National Weather Service Observing Handbook No.1, Marine Surface Observations
    Y c. a weather forecast
    N d. the sky overhead

1807: Which weather system produces strong cold winds called "Northers" during the winter months in the Gulf of Mexico?

    N a. A polar maritime air mass
    Y b. A high pressure system
    N c. A cyclone
    N d. A low pressure system

1836: At evening stars, the first stars that should be observed are those with an azimuth in what quadrant?

    N a. Southern
    N b. Western
    N c. Northern
    Y d. Eastern

1890: A vessel heading SSE is on a course of __________.

    N a. 112.5°
    N b. 135.0°
    Y c. 157.5°
    N d. 180.0°

1979: The principal vertical circle is that great circle on the celestial sphere that passes through the __________.

    N a. zenith and the celestial body
    Y b. zenith and the north and south poles
    N c. poles and Greenwich
    N d. zenith and is parallel to the horizon

1996: When approaching a lock entrance, the visual signal displayed when a single lock is ready for entrance is a flashing __________.

    N a. red light
    Y b. green light
    N c. amber light
    N d. white light

2080: You are on course 030°T. The relative bearing of a lighthouse is 45°. What is the true bearing?

    N a. 015°
    Y b. 075°
    N c. 255°
    N d. 345°

2130: You are underway and pass by a lighthouse. Its light, which was white since you first sighted it, changes to red. This means __________.

    N a. the light is characterized as alternately flashing
    N b. the lighthouse has lost power and has switched to emergency lighting
    N c. it is the identifying light characteristic of the lighthouse
    Y d. you have entered an area of shoal water or other hazard

2199: Denebola is found in what constellation?

    N a. Hydrus
    Y b. Leo
    N c. Centaurus
    N d. Aquila

2229: A vessel is heading magnetic north and its magnetic compass indicates a heading of 003°. What action should be taken to remove this error during compass adjustment?

    Y a. If the red ends are to port the athwartships magnets should be raised.
    N b. If the blue ends are to port the athwartships magnets should be raised.
    N c. If the red ends are forward the fore-and-aft magnets should be lowered.
    N d. If the blue ends are forward the fore-and-aft magnets should be raised.

2234: A vessel is heading magnetic north and its magnetic compass indicates a heading of 003°. What action should be taken to remove this error during compass adjustment?

    N a. Move the quadrantal spheres closer to the compass
    N b. Raise the heeling magnet if the red end is up
    N c. Remove some of the Flinders bar
    Y d. Raise or lower the athwartship magnets

2274: A vessel is heading magnetic east and its magnetic compass indicates a heading of 086°. What action should be taken to remove this error during compass adjustment?

    N a. If the red ends of the magnets are to port you should lower the athwartships tray.
    N b. If the blue ends of the magnets are to port, and the athwartships tray is at the top, you should reverse the magnets.
    N c. If the red ends of the magnet are aft, and the fore-and-aft tray is at the top, you should add some more magnets.
    Y d. If the red ends of the magnets are aft you should lower the fore-and-aft tray.

2496: An orange and white buoy marking a danger area will have what symbol on it?

    Y a. Open-faced diamond
    N b. Diamond with a cross
    N c. Circle
    N d. Square

2627: Stormy weather is usually associated with regions of __________.

    N a. high barometric pressure
    Y b. low barometric pressure
    N c. steady barometric pressure
    N d. changing barometric pressure

2688: The 10-cm radar as compared to a 3-cm radar of similar specifications will __________.

    N a. be more suitable for river and harbor navigation
    N b. provide better range performance on low lying targets during good weather and calm seas
    Y c. have a wider horizontal beam width
    N d. have more sea return during rough sea conditions

2752: A daymark used to indicate the safe water in a channel will have which of the shapes shown? (D045NG )

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

2792: You take a bearing of 142° and 259° of two objects. Which bearing of a third object will give the best fix?

    N a. 081°
    N b. 238°
    Y c. 201°
    N d. 234°

2923: You should plot your dead reckoning position __________.

    N a. from every estimated position
    Y b. from every fix or running fix
    N c. every three minutes in pilotage waters
    N d. only in pilotage waters

3079: With respect to failure warnings and status indications, GPS receivers should provide, at a minimum, __________.

    N a. an indication within 5 seconds if the specified HDOP has been exceeded
    N b. a warning of loss of position
    N c. a differential GPS status indication of the receipt of DGPS signals
    Y d. All of the above

3087: With respect to failure warnings and status indications, GPS receivers should provide, at a minimum, __________.

    Y a. a warning of loss of position
    N b. a cross-track error alarm
    N c. an indication of a change in satellite configuration
    N d. an alarm if engine speed is suddenly reduced

3087: With respect to failure warnings and status indications, GPS receivers should provide, at a minimum, __________.

    Y a. a warning of loss of position
    N b. a cross-track error alarm
    N c. an indication of a change in satellite configuration
    N d. an alarm if engine speed is suddenly reduced

3106: What does an automatic identification system (AIS) transponder use to transmit and receive information broadcasts?

    N a. 3000 Mhz and 9200 Mhz
    N b. 2182 Khz and 2187.5 Khz
    Y c. 156.525 Mhz, 161.975 Mhz and 162.025 Mhz
    N d. 1575.42 Mhz and 1227.6 Mhz

3114: With respect to automatic identification systems (AIS), which information is expected to be broadcast every 1 to 10 seconds?

    N a. Rate of turn
    N b. Latitude and longitude
    N c. Navigational status
    Y d. All of the above