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.


45: The navigator aboard a ship at approximately 165°E longitude observes the Sun at ZT 14-25-04 on 21 September. What is the GMT and Greenwich date of the observation?


240: In a river subject to tidal currents, the best time to dock a ship without the assistance of tugs is __________.


386: Your vessel is on course 180°T speed 22 knots. The apparent wind is from 70° off the port bow, speed 20 knots. The true direction and speed of the wind are __________.


494: Aneroid barometers are usually calibrated to indicate atmospheric pressure in __________.

    N a. inches of mercury and centimeters
    N b. feet of mercury and millibars
    N c. inches of mercury and millimeters
    Y d. inches of mercury and millibars

511: A survey (special purpose mark) buoy __________.

    N a. must be lighted
    N b. may have a flashing red light
    N c. may have a fixed white light
    Y d. None of the above

527: On 6 June 1983, at 1719 EST (ZD +5), what will be the predicted height of tide at Chester, PA?

    N a. 0.8 feet( 0.2 meters)
    Y b. 1.1 feet (0.3 meters)
    N c. 3.5 feet (1.1 meters)
    N d. 4.7 feet (1.4 meters)

528: What should you expect when you encounter a tsunami in the open ocean?

    N a. Violent seas from mixed directions
    Y b. No noticeable change from the existing sea state
    N c. Winds increasing to gale force from the northwest in the Northern Hemisphere
    N d. A major wave of extreme height and length

537: What will be the height of tide at Gargathy Neck, VA, at 1800 DST (ZD +4), on 16 August 1983?

    N a. 2.3 feet
    Y b. 2.9 feet
    N c. 3.3 feet
    N d. 3.6 feet

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

    Y a. radar transponder beacon
    N b. radar conspicuous beacon
    N c. radar calibration beacon
    N d. circular radio beacon

557: Your vessel has a draft of 23 feet. On 23 June 1983 you wish to pass over a temporary obstruction near Beaufort, SC, that has a charted depth of 22 feet. Allowing for a safety margin of 3 feet, what is the earliest time after 1600 DST (ZD +4) that this passage can be made?

    Y a. 1750
    N b. 1815
    N c. 1855
    N d. 1944

566: You are attempting to locate your position relative to a hurricane in the Northern Hemisphere. If the wind direction remains steady, but with diminishing velocity, you are most likely __________.

    N a. in the right semicircle
    N b. in the left semicircle
    N c. on the storm track ahead of the center
    Y d. on the storm track behind the center

624: When using a mechanical (windup type) marine chronometer, how often should it be reset?

    Y a. Only when it is overhauled
    N b. Whenever the chronometer error exceeds approximately four minutes
    N c. At the start of each voyage
    N d. If the chronometer rate changes from gaining to losing or vice versa

633: You have another ship overtaking you close aboard to starboard. You have 3 radar targets bearing 090° relative at ranges of .5 mile, 1 mile, and 1.5 miles. In this case, the unwanted echoes are called __________.

    Y a. multiple echoes
    N b. spoking
    N c. indirect echoes
    N d. side-lobe echoes

646: You have determined that you are in the right semicircle of a tropical cyclone in the Northern Hemisphere. What action should you take to avoid the storm?

    N a. Place the wind on the starboard quarter and hold that course.
    N b. Place the wind on the port quarter and hold that course.
    N c. Place the wind on the port bow and hold that course.
    Y d. Place the wind on the starboard bow and hold that course.

764: Magnetic variation changes with a change in __________.

    N a. the vessel's heading
    N b. sea conditions
    N c. seasons
    Y d. the vessel's position

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

867: Which ocean current is "warm" based on the latitude in which it originates and on the effect it has on climate?

    Y a. Kuroshio Current
    N b. Benguela Current
    N c. Peru Current
    N d. California Current

897: What current flows southward along the west coast of the United States and causes extensive fog in that area?

    N a. Davidson Current
    N b. North Pacific Current
    N c. Alaska Current
    Y d. California Current

955: The line of position determined from a sight with an observed altitude (Ho) of 88°45.0' should be __________.

    N a. reduced to the meridian and plotted as a latitude line
    N b. calculated as a longitude line
    N c. plotted by using an intercept from an assumed position
    Y d. plotted as an arc around the GP of the body

1008: The Light List indicates that a light has a nominal range of 18 miles and is 38 feet high. If the visibility is 6 miles and your height of eye is 15 feet, at which distance will you sight the light?

    N a. 18.0 nm
    N b. 14.8 nm
    Y c. 11.7 nm
    N d. 6.0 nm

1037: Generally speaking, a ship steaming across the North Pacific from Japan to Seattle is likely to experience __________.

    N a. adverse currents for practically the entire crossing
    Y b. favorable currents for practically the entire crossing
    N c. favorable currents in the summer months and adverse currents in the winter months
    N d. variable currents having no significant effect on the total steaming time

1095: The celestial coordinate of a star that is relatively constant in value is the __________.

    N a. Greenwich hour angle
    N b. local hour angle
    Y c. sidereal hour angle
    N d. meridian angle

1103: The vertical component of the Earth's magnetic field causes induced magnetism in vertical soft iron. This changes with latitude. What corrects for this coefficient of the deviation?

    Y a. The Flinders bar
    N b. The heeling magnet
    N c. Quadrantal soft iron spheres
    N d. Bar magnets in the binnacle

1118: When entering from seaward, a buoy displaying a single-flashing red light indicates __________.

    N a. a junction with the preferred channel to the left
    Y b. the starboard side of the channel
    N c. a sharp turn in the channel to the right
    N d. a wreck to be left on the vessel's port side

1216: In the Northern Hemisphere, winds veering sharply to the west or northwest with increasing speed are indications that a __________.

    Y a. cold front has passed
    N b. low pressure center is approaching
    N c. stationary front exists
    N d. high pressure center has passed

1258: You should log all barometer readings taken at sea __________.

    N a. regularly
    N b. at least once during each watch
    N c. more often under changeable weather conditions
    Y d. All of the above

1271: Which word indicates color variation in the characteristics of a light?

    N a. Opposing
    N b. Changing
    N c. Reversing
    Y d. Alternating

1392: Cumulonimbus clouds are indicated by which number? (D039NG )

    Y a. 9
    N b. 7
    N c. 5
    N d. 3

1399: You are bound for Baltimore via Cape Henry on a 15 knot ship. If the flood at Chesapeake Bay entrance begins at 1800 EST (ZD +5), at what time would you depart from the Chesapeake Bay entrance to have the most favorable current?

    N a. 1700 hours
    N b. 1800 hours
    N c. 1900 hours
    Y d. 2030 hours

1475: Which type of cloud is the classic "thunderhead"?

    Y a. Cumulonimbus
    N b. Stratus
    N c. Cirrus
    N d. Altostratus

1576: You are entering an east coast port and see a buoy with a yellow triangle painted on it. This indicates __________.

    Y a. you are in the vicinity of the ICW
    N b. the buoy is a special mark
    N c. the buoy is off station
    N d. the buoy designates a sharp turn in the channel

1648: A sign of thunderstorm development is a cumulus cloud __________.

    N a. darkening, growing in size and forming an anvil top
    N b. that shows extensive vertical development
    N c. creating cold downdrafts that are felt on the ground
    Y d. All of the above

1678: Which information is NOT provided in broadcasts by the National Institute of Standards and Technology?

    N a. Storm Warnings
    N b. Time Announcements
    N c. GPS Information
    Y d. NAVAREA Warnings

1684: Which type of frontal passage is associated with a relatively narrow band of precipitation?

    Y a. A cold front
    N b. A warm front
    N c. A stationary front
    N d. None of the above

1700: Generally speaking, you should expect to find low atmospheric pressure prevailing in the earth's __________.

    Y a. equatorial area
    N b. polar regions
    N c. mid-latitudes
    N d. All of the above

1752: What is the major limitation in using the Sight Reduction Tables for Air Navigation Volume I (Pub. No. 249) for star sights?

    N a. More accuracy is needed for celestial observations on board ship than what is tabulated.
    N b. Sights must be made at even time increments to benefit from the tables.
    Y c. Only certain stars are included and sights must be limited to those stars.
    N d. Only first magnitude stars are tabulated.

1784: If your vessel were proceeding down river (descending), a green square marker with a green reflector border on the right bank would be a __________.

    N a. mile board
    N b. dredging mark
    Y c. passing daymark
    N d. crossing daymark

1832: Which magnetic compass corrector(s) can be set while the vessel is on a heading of magnetic northeast or magnetic southeast?

    N a. Flinders bar
    N b. Heeling magnets
    N c. Fore-and-aft magnets
    Y d. Quadrantal spheres

1972: The point on the celestial sphere that is directly over the observer is the __________.

    N a. node
    N b. pole
    Y c. zenith
    N d. nadir

2079: Permission to enter the riverward chamber of twin locks is given by the lockmaster and consists of which sound signal?

    N a. One short blast
    N b. Two short blasts
    N c. One long blast
    Y d. Two long blasts

2144: Yesterday your chronometer read 02h 59m 58s at the 1500 GMT time tick. Today the chronometer reads 03h 00m 02s at the 1500 GMT time tick. What is the chronometer error?

    Y a. 02s fast
    N b. 03h 00m 02s fast
    N c. +3s
    N d. -3s

2165: The illustration represents a movable dam. If there is high water and the wickets are down so that there is an unobstructed navigable pass through the dam, what light(s) will be shown at B if the lock walls and piers are not awash? (D037NG )

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

2180: Relative humidity is defined as __________.

    N a. the maximum vapor content the air is capable of holding
    N b. the minimum vapor content the air is capable of holding
    Y c. the ratio of the actual vapor content at the current temperature to the air's vapor holding capability
    N d. the relation of the moisture content of the air to barometric pressure

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

2258: The primary use of apparent time in marine navigation is to __________.

    N a. calculate sunrise or sunset
    N b. determine zone time
    N c. enter an almanac
    Y d. determine the time of meridian transit

2258: The primary use of apparent time in marine navigation is to __________.

    N a. calculate sunrise or sunset
    N b. determine zone time
    N c. enter an almanac
    Y d. determine the time of meridian transit

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

2316: Elongation becomes zero at __________.

    N a. opposition
    N b. west quadrature
    N c. apogee
    Y d. inferior conjunction

2504: Under the IALA-A Buoyage System, when entering from seaward a lateral system buoy to be left to starboard may display which topmark shown? (D046NG )

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

2522: The letter H in illustration D006NG represents the __________. (D006NG )

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

2588: You are approaching an open drawbridge and sound the proper signal. You receive no acknowledgment from the bridge. Which action should you take?

    Y a. Approach with caution and proceed through the open draw.
    N b. Approach under full control to a position no closer than 400 yards from the bridge and await a signal from the bridge.
    N c. Hold in the channel as a vessel is closing the bridge from the other direction.
    N d. Resound the opening signal and do not pass through the bridge until signals have been exchanged.

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

2737: A lateral system buoy displaying a quick light __________.

    N a. should be passed close aboard on either side
    Y b. indicates that special caution is required
    N c. is used at a channel bifurcation or junction
    N d. is painted with red and white vertical stripes

2772: The direction in which a vessel should be steered between two points is the __________.

    Y a. course
    N b. heading
    N c. bearing
    N d. course over the ground

2895: A white buoy with an orange rectangle on it is a(n) __________.

    N a. junction buoy
    N b. safe water buoy
    Y c. informational buoy
    N d. All of the above

2913: The Daily Memorandum contains information on __________.

    N a. active weather disturbances such as hurricanes or tropical storms
    Y b. the latest navigational warnings
    N c. scheduled vessel arrivals and departures for a 24-hour period
    N d. water levels at river ports where run-off affects tidal heights

2972: You are in a channel inbound from sea. A daymark used to mark a channel junction when the preferred channel is to starboard will have the shape indicated by what letter in illustration D045NG?

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

3009: "Proceeding from seaward" for the purpose of the direction of buoying offshore, lateral system buoys would be proceeding __________.

    N a. northerly on the Atlantic Coast
    N b. easterly on the Gulf Coast
    Y c. northerly on the Pacific Coast
    N d. None of the above

3023: You have steadied up on a range dead ahead in line with your keel. After a few minutes the range, still dead ahead, appears as shown. Which action do you take? (D047NG )

    Y a. Alter heading to the left
    N b. Alter heading to the right
    N c. Increase speed
    N d. Maintain heading, keeping the range dead ahead

3125: Which of the following statements is TRUE regarding automatic identification systems (AIS)?

    N a. AIS is designed to replace ARPA, maneuvering boards, and visual bearings as a means to ascertain the risk of collision.
    Y b. AIS provides near real-time information regarding another vessel's speed over ground and heading regardless of visibility.
    N c. AIS will not provide information on another vessel if that vessel is indistinguishable in radar sea clutter.
    N d. AIS can be relied upon as the sole means to determine course changes due to other AIS equipped traffic.