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.


13: Most modern Loran-C receivers, when not tracking properly, have a(n) __________.


66: What will a veering wind do?


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


143: Under the IALA - A Buoyage System, a buoy used as a port hand mark would not show which light characteristic?

    N a. Isophase
    N b. Quick flashing
    N c. Long flashing
    Y d. Group Flashing (2 + 1)

316: According to Buys Ballot's law, when an observer in the Northern Hemisphere experiences a northwest wind, the center of low pressure is located to the __________.

    Y a. northeast
    N b. west-southwest
    N c. northwest
    N d. south-southeast

346: If your weather bulletin shows the center of a low pressure area to be 100 miles due east of your position, what winds can you expect in the Northern Hemisphere?

    N a. East to northeast
    N b. East to southeast
    Y c. North to northwest
    N d. South to southeast

397: The mean tide level at Peaks Island, ME, is __________.

    N a. 1.8 feet (0.5 meters)
    N b. 2.5 feet (0.8 meters)
    N c. 3.2 feet (1.0 meters)
    Y d. 4.5 feet (1.4 meters)

464: Prior to reading an aneroid barometer, you should tap the face lightly with your finger to __________.

    N a. expose any loose connections
    N b. demagnetize the metal elements
    Y c. bring the pointer to its true position
    N d. contract and expand the glass face

483: Coral atolls, or a chain of islands at right angles to the radar beam, may show as a long line rather than as individual targets due to __________.

    Y a. the effects of beam width
    N b. limitations on range resolution
    N c. the pulse length of the radar
    N d. the multiple-target resolution factor

505: The error in the measurement of the altitude of a celestial body, caused by refraction, increases as the __________.

    N a. horizontal parallax decreases
    N b. observer's height above sea level increases
    N c. humidity of the atmosphere decreases
    Y d. altitude of the body decreases

517: On 5 March 1983, at 0630 EST (ZD +5), what will be the predicted height of tide at Ocracoke, Ocracoke Inlet, NC?

    Y a. 0.1 foot
    N b. 1.2 feet
    N c. 1.9 feet
    N d. 2.3 feet

517: On 5 March 1983, at 0630 EST (ZD +5), what will be the predicted height of tide at Ocracoke, Ocracoke Inlet, NC?

    Y a. 0.1 foot
    N b. 1.2 feet
    N c. 1.9 feet
    N d. 2.3 feet

525: In the celestial equator system of coordinates, what is comparable to latitude on the terrestrial sphere?

    N a. Altitude
    N b. Right ascension
    N c. Celestial meridians
    Y d. Declination

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

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

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

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)

602: Between the equator and the 46th parallel of latitude, there are 3099 meridional parts. How many degrees of equatorial longitude does 3099 meridional parts represent?

    N a. 35°52'45"
    Y b. 51°39'00"
    N c. 74°21'11"
    N d. 82°36'12"

626: What indicates the arrival of a hurricane within 24 to 36 hours?

    N a. The normal swell becoming lower and from a steady direction
    N b. Long bands of nimbostratus clouds radiating from a point over the horizon
    N c. The barometer drops 2 millibars between 1000 and 1600
    Y d. Unusually good weather with above average pressures followed by a slow fall of 4 millibars in six hours

647: You will enter Argentia, Newfoundland, at 1200 on 5 October 1983, while keeping zone description +3 on the ship's clocks. What will be the height of tide at this time (based on the Canadian chart datum)?

    N a. 0.5 feet
    N b. 1.2 feet
    Y c. 2.1 feet
    N d. 3.4 feet

669: It is desirable that a vessel encountering hurricane or typhoon conditions sends weather reports to the closest meteorological service at least every __________.

    N a. hour
    Y b. 3 hours
    N c. 6 hours
    N d. 8 hours

687: The drift and set of tidal, river, and ocean currents refer to the __________.

    N a. position and area of the current
    Y b. speed and direction toward which the current flows
    N c. type and characteristic of the current's flow
    N d. None of the above

697: The set of the current is the __________.

    N a. speed of the current at a particular time
    N b. maximum speed of the current
    N c. direction from which the current flows
    Y d. direction in which the current flows

701: In the IALA Buoyage System, buoys with alternating red and green horizontal bands are used to indicate __________.

    N a. fishing areas
    N b. spoil grounds
    Y c. the preferred channel
    N d. isolated dangers

773: What is the basic principle of the magnetic compass?

    Y a. Magnetic materials of the same polarity repel each other and those of opposite polarity attract.
    N b. The Earth's magnetic lines of force are parallel to the surface of the Earth.
    N c. Magnetic meridians connect points of equal magnetic variation.
    N d. The compass needle(s) will, when properly compensated, lie parallel to the isogonic lines of the Earth.

779: Which sextant shown has an index error of 0'20" on the arc? (D050NG )

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

780: Apparent wind speed blowing across your vessel while underway can be measured by a(n) __________.

    N a. barometer
    N b. wind vane
    Y c. anemometer
    N d. thermometer

833: The magnetic compass magnets are acted on by the horizontal component of the Earth's total magnetic force. This magnetic force is GREATEST at the __________.

    N a. north magnetic pole
    N b. south magnetic pole
    N c. magnetic prime vertical meridian
    Y d. magnetic equator

869: Tropical storms and hurricanes are most likely to form in the Southern hemisphere during __________.

    Y a. January through March
    N b. April through May
    N c. June through August
    N d. September through November

998: The navigable semicircle of a tropical storm in the South Indian Ocean is located on which side of the storm's track?

    N a. Rear
    N b. Front
    N c. Left
    Y d. Right

1055: The radius of a circle of equal altitude for a body equals the body's __________.

    N a. declination
    N b. polar distance
    N c. altitude
    Y d. zenith distance

1081: On a voyage along the coast of France, you sight a buoy with the top marks as shown. You are required to steer __________. (D026NG )

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

1094: A light, feathery deposit of ice caused by the sublimation of water vapor directly into the crystalline form, on objects whose temperatures are below freezing, is called __________.

    N a. dew
    Y b. frost
    N c. glaze
    N d. snow

1182: Referring to the illustration, which wind speed is reported in position C? (D049NG )

    N a. 3 knots
    N b. 10 knots
    N c. 20 knots
    Y d. 30 knots

1203: If the compass heading and the magnetic heading are the same then __________.

    N a. the deviation has been offset by the variation
    N b. there is something wrong with the compass
    N c. the compass is being influenced by nearby metals
    Y d. there is no deviation on that heading

1215: Daylight savings time is a form of zone time that adopts the time __________.

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

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

1232: Entering from seaward, triangular-shaped daymarks are used to mark __________.

    Y a. the starboard side of the channel
    N b. the centerline of the channel
    N c. an obstruction where the preferred channel is to starboard
    N d. special purpose areas

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

1379: The lubber's line on a magnetic compass indicates __________.

    N a. compass north
    Y b. the direction of the vessel's head
    N c. magnetic north
    N d. a relative bearing taken with an azimuth circle

1503: A radar range to a small, charted object such as a light will provide a line of position in which form?

    N a. Straight line
    Y b. Arc
    N c. Parabola
    N d. Hyperbola

1627: An instrument that maintains a continuous record of humidity changes is called a __________.

    N a. thermometer
    N b. barometer
    Y c. hygrograph
    N d. thermograph

1634: A lighted buoy to be left to starboard, when entering a U.S. port from seaward, shall have a __________.

    Y a. red light
    N b. white light
    N c. green light
    N d. light characteristic of Morse (A)

1737: You can determine if your vessel's position is in the dangerous or navigable semicircle of a hurricane by __________.

    N a. observing whether the wind is veering or backing
    N b. plotting two or more recent storm positions from weather bulletins
    Y c. Both A and B
    N d. Neither A nor B

1809: What occurs when rising air cools to the dew point?

    N a. Advection fog forms
    N b. Humidity decreases
    N c. Winds increase
    Y d. Clouds form

2067: The Light List indicates that a light has a nominal range of 10 miles and is 11 feet high. If the visibility is 5 miles and your height of eye is 20 feet, at what approximate distance will you sight the light?

    Y a. 6.3 miles
    N b. 7.4 miles
    N c. 8.4 miles
    N d. 9.0 miles

2271: What is the definition of height of tide?

    N a. The vertical distance from the surface of the water to the ocean floor
    Y b. The vertical distance from the tidal datum to the level of the water at any time
    N c. The vertical difference between a datum plane and the ocean bottom
    N d. The vertical difference between the heights of low and high water

2338: A group of stars which appear close together and form a striking configuration such as a person or animal is a __________.

    N a. cluster
    N b. shower
    Y c. constellation
    N d. galaxy

2446: What is the equivalent of 47 min. 20 sec. in arc units?

    N a. 8°27'
    Y b. 11°50'
    N c. 13°42'
    N d. 13°56'

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

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

2525: Daylight savings time is a form of zone time that adopts the time __________.

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

2562: In the time diagram shown __________. (D005NG )

    N a. the GHA of the Sun is approximately 330°
    Y b. your date is one day later than the date at Greenwich
    N c. the LHA of the Sun is approximately 120°
    N d. you are in west longitude

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.

2651: Low pressure disturbances which travel along the intertropical convergence zone are called __________.

    Y a. tropical waves
    N b. tropical disturbances
    N c. permanent waves
    N d. tidal waves

2778: A special daymark is a __________.

    N a. red-and-white octagon
    N b. daymark with a yellow stripe on it
    N c. green square
    Y d. yellow diamond

2858: While navigating in fog off a coastline of steep cliffs, you hear the echo of the ships fog horn 2 1/2 seconds after the signal was sounded. What is the distance to the shore?

    N a. 225 yards
    Y b. 460 yards
    N c. 750 yards
    N d. 910 yards

2938: You take a bearing of 176° of a lighthouse. What bearing of another object would give the best fix?

    N a. 000°
    N b. 021°
    N c. 189°
    Y d. 272°

3019: Where would you find information about the time of high tide at a specific location on a particular day of the year?

    Y a. Tide Tables
    N b. Tidal Current Tables
    N c. Coast Pilot
    N d. Nautical Almanac

3061: In a river subject to tidal currents, the best time to dock a ship without the assistance of tugs is __________.

    N a. at flood tide
    N b. at high water
    N c. when there is a following current
    Y d. at slack water