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.


5: A vessel is steaming in east longitude on January 25 and crosses the International Date Line on an eastbound course at 0900 zone time. What is the date and time at Greenwich when the vessel crosses the line?


6: Wind velocity varies __________.


15: What is the length of a nautical mile?


72: The datum from which the predicted heights of tides are reckoned in the tide tables is __________.

    N a. mean low water
    Y b. the same as that used for the charts of the locality
    N c. the highest possible level
    N d. given in table three of the tide tables

74: When operated over a muddy bottom, a fathometer may indicate __________.

    N a. a shallow depth reading
    N b. a zero depth reading
    N c. no depth reading
    Y d. two depth readings

125: The GMT is 0445 and your zone description is +1. Your zone time is __________.

    N a. 0445
    Y b. 0345
    N c. 0545
    N d. 1545

271: Your vessel is leaving New York harbor in dense fog. As the vessel slowly proceeds toward sea, you sight a green can buoy on the starboard bow. Which action should you take?

    N a. Turn hard right to get back into the channel.
    N b. Pass the buoy close to, leaving it to your port.
    N c. Stop and fix your position.
    Y d. Stand on, leaving the buoy to your starboard.

331: What indicates a buoy that should be left to port when entering from seaward? (U.S. Aids to Navigation System)

    N a. White light
    N b. Group flashing characteristic
    N c. Nun shape
    Y d. Odd number

364: What causes the error of collimation with regards to the four adjustments to a sextant?

    Y a. Telescope not parallel to the frame
    N b. Personal error
    N c. The frame and index mirror not perpendicular
    N d. The frame and horizon glass not perpendicular

395: If the Sun's observed altitude is 27°12', the zenith distance is __________.

    Y a. 62°48'
    N b. 27°12'
    N c. 152°48'
    N d. 43°12'

487: What will be the time after 0600 (ZD +3), on 6 March 1983, that the height of the tide at Puerto Rosales, Argentina, will be 9.0 feet (2.7 meters)?

    N a. 0740
    N b. 0754
    N c. 0840
    Y d. 0922

549: On a working copy of a weather map, an occluded front is represented by which color line?

    N a. Red
    N b. Blue
    N c. Alternating red and blue
    Y d. Purple

571: The Coast Guard Captain of the Port has excluded all traffic from a section of a port, while a regatta is taking place. The buoys marking this exclusion area will be __________.

    N a. nun- or can-shaped to conform to the overall direction of navigation
    N b. yellow
    Y c. orange and white
    N d. marked with a spherical topmark

594: Barometers are calibrated at a standard temperature of __________.

    N a. 0°F
    Y b. 32°F
    N c. 60°F
    N d. 70°F

595: In the navigational triangle, the angle at the elevated pole is the __________.

    Y a. meridian angle
    N b. altitude
    N c. right ascension
    N d. azimuth angle

691: Of the four light characteristics shown which one does NOT represent a safe water mark of the IALA Buoyage System? (D019NG )

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

693: Which general statement concerning radar is FALSE?

    N a. Raising the antenna height increases the radar range.
    Y b. The ability of radar to detect objects is unaffected by weather conditions.
    N c. Radar bearings are less accurate than radar ranges.
    N d. Radar should be checked regularly during clear weather to ensure that it is operating properly.

704: What is TRUE of the history display of a target's past positions on an ARPA?

    N a. It provides a graphic display to emphasize which vessel is on a collision course.
    Y b. In the true presentation, it provides a quick visual check to determine if a vessel has changed course.
    N c. The display is one of the primary inputs and must be in use when using the trial maneuver capability.
    N d. It provides a graphic display of a target vessel's relative course, speed, and CPA.

707: Set of the current is __________.

    N a. its velocity in knots
    N b. direction from which it flows
    N c. estimated current
    Y d. direction towards which it flows

740: A very light breeze that causes ripples on a small area of still water is a __________.

    Y a. cat's paw
    N b. hog's breath
    N c. williwaw
    N d. chinook

818: Ocean swells originating from a typhoon can move ahead of it at speeds near __________.

    N a. 10 knots
    N b. 20 knots
    N c. 30 knots
    Y d. 50 knots

840: Which position includes the effects of wind and current?

    Y a. Estimated position
    N b. Set position
    N c. Leeway position
    N d. Dead reckoning position

851: You would expect to find channels marked with the IALA-A Buoyage System in __________.

    N a. the Philippines
    Y b. Australia
    N c. Republic of Korea
    N d. Chile

983: Error may be introduced into a magnetic compass by __________.

    N a. making a structural change to the vessel
    N b. a short circuit near the compass
    N c. belt buckles
    Y d. All of the above

999: You are preparing a weather report form, WS Form B-80. Three-quarters of the sky is covered with clouds, and the anemometer indicates that the apparent wind is from 226° relative at 17.7 knots. You are on course 020°T at 8 knots. How should you encode group Nddff? (D041NG )

    N a. 80208
    N b. 72218
    N c. 72318
    Y d. 62324

1048: The velocity of the current in large coastal harbors is __________.

    N a. unpredictable
    N b. generally too weak to be of concern
    Y c. predicted in Tidal Current Tables
    N d. generally constant

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

1219: Which sextant in illustration D043NG reads 29°42.5'? (D043NG )

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

1226: Cumulonimbus clouds are most likely to accompany a(n) __________.

    N a. high pressure system
    Y b. cold front
    N c. warm front
    N d. occluded front

1233: Deviation is the angle between the __________.

    N a. true meridian and the axis of the compass card
    N b. true meridian and the magnetic meridian
    Y c. magnetic meridian and the axis of the compass card
    N d. axis of the compass card and the degaussing meridian

1266: A line of clouds, sharp changes in wind direction, and squalls are most frequently associated with a(n) __________.

    N a. occluded front
    N b. warm front
    Y c. cold front
    N d. warm sector

1313: Variation in a compass is caused by __________.

    N a. worn gears in the compass housing
    Y b. magnetism from the earth's magnetic field
    N c. magnetism within the vessel
    N d. lack of oil in the compass bearings

1324: When daylight savings time is kept, the time of tide and current calculations must be adjusted. One way of doing this is to __________.

    Y a. add one hour to the times listed under the reference stations
    N b. subtract one hour from the time differences listed for the subordinate stations
    N c. apply no correction as the times in the reference stations are adjusted for daylight savings time
    N d. add 15° to the standard meridian when calculating the time difference

1350: You are running parallel to the coast and plotting running fixes using bearings of the same object. You are making more speed than assumed for the running fix. In relation to the position indicated by the fix you will be __________.

    N a. closer to the coast
    Y b. farther from the coast
    N c. on the track line ahead of the fix
    N d. on the track line behind the fix

1382: The chart indicates the variation was 3°45'W in 1988, and the annual change is increasing 6'. If you use the chart in 1991 how much variation should you apply?

    N a. 3°27'W
    N b. 3°27'E
    Y c. 4°03'W
    N d. 4°03'E

1402: As a vessel changes course to starboard, the compass card in a magnetic compass __________.

    N a. first turns to starboard then counterclockwise to port
    N b. also turns to starboard
    N c. turns counterclockwise to port
    Y d. remains aligned with compass north

1416: Radiation fog __________.

    N a. always forms over water
    Y b. is formed by a temperature inversion
    N c. is thinnest at the surface
    N d. dissipates during the evening

1421: What is the approximate geographic visibility of an object with a height above the water of 70 feet, for an observer with a height of eye of 65 feet?

    N a. 16.8 nm
    Y b. 19.0 nm
    N c. 20.6 nm
    N d. 22.4 nm

1449: The presence of stratus clouds and a dying wind will usually result in __________.

    N a. heavy rain
    N b. heavy snow
    Y c. thick fog
    N d. clearing skies

1467: Determine the time after 0730 EST (ZD +5) when the velocity of the current will be 2.1 knots on 26 March 1983, at Fort Pulaski, GA.

    N a. 0802
    N b. 0812
    N c. 0821
    Y d. 0840

1499: You are scanning the radar screen for a buoy fitted with racon. How should this signal appear on the PPI display?

    Y a. Starting with a dash and extending radially outward from the target
    N b. As a broken line from center of PPI to the target
    N c. Starting with a dot and extending radially inward from the target
    N d. Starting with a dash and extending to the right of the target

1569: Three or four feet of the total height of a storm surge in a hurricane can be attributed to __________.

    N a. an increase in temperature
    N b. an increase in the wave period
    N c. the wind velocity
    Y d. the decrease in atmospheric pressure

1624: A psychrometer has two thermometers that provide dry bulb and wet bulb temperatures. By comparing these two temperature readings with a set of tables you can determine the __________.

    N a. atmospheric pressure
    N b. wind speed
    Y c. relative humidity and dew point
    N d. wind chill factor

1631: Which picture shows an occulting light? (D034NG )

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

1642: Which type of cloud formation should be of immediate concern to small craft operators?

    N a. cirrus
    N b. altostratus
    N c. nimbostratus
    Y d. cumulonimbus

1658: Fog forms when the air temperature is at or below __________.

    N a. 32° F
    N b. the wet bulb temperature
    Y c. the dew point
    N d. the dry bulb temperature

1667: Air masses near the earth's surface __________.

    N a. move from areas of high pressure to areas of low pressure
    N b. are deflected by the earth's rotation in both hemispheres
    N c. are deflected by the "Coriolis effect"
    Y d. All of the above

1699: In the Northern Hemisphere, when the center of a high pressure system is due east of your position, you can expect winds from the __________.

    N a. south to west
    Y b. south to east
    N c. north to west
    N d. north to east

1786: You are downbound approaching a lock and see 3 green lights in a vertical line. This indicates __________.

    N a. that the lock chamber is open and ready to receive your tow
    N b. that you should hold up until the signal changes to 2 green lights
    Y c. the upstream end of the river wall
    N d. the upstream end of the land wall

1810: Where will you find information about the duration of slack water?

    N a. Tide Tables
    N b. Sailing Directions
    Y c. Tidal Current Tables
    N d. American Practical Navigator

2268: What condition exists at perigee?

    N a. The Earth is farthest from the Sun.
    N b. The Earth, Sun, and Moon are in line.
    N c. The Earth, Sun, and Moon are at right angles.
    Y d. The Moon is closest to the Earth.

2286: Which light signal indicates that you have permission to enter a lock on the Ohio River?

    N a. Steady red
    N b. Flashing amber
    N c. Steady green
    Y d. Flashing green

2309: The plane of the ecliptic is inclined to the plane of the celestial equator by what angle?

    N a. 00°23'
    Y b. 23°27'
    N c. 45°00'
    N d. 90°00'

2374: The largest of the navigational planets is __________.

    N a. Mars
    N b. Venus
    Y c. Jupiter
    N d. Saturn

2683: A vessel's position should be plotted using bearings of __________.

    N a. buoys close at hand
    Y b. fixed known objects on shore
    N c. fixed objects
    N d. All of the above

2739: A daymark used to indicate the starboard side of the channel when approaching from seaward will have the shape indicated by what letter in illustration D045NG?

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

2780: You are pushing a tow ahead and passing close to another towboat which is pushing ahead in the same direction (you are overtaking). After the towheads pass close alongside __________.

    N a. you will gain speed
    N b. both boats will gain speed
    N c. the tows will tend to drift apart
    Y d. the tows will tend to drift together

2842: The draw span of a floating drawbridge may be marked with __________.

    N a. two white lights
    Y b. a yellow diamond
    N c. flashing blue lights
    N d. three red lights on each side of the draw

2945: A position that is obtained by applying estimated current and wind to your vessel's course and speed is a(n) __________.

    Y a. estimated position
    N b. dead reckoning position
    N c. fix
    N d. None of the above

3060: What information is NOT found in the chart title?

    N a. Survey information
    N b. Scale
    Y c. Date of first edition
    N d. Projection