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?


10: The wind at Frying Pan shoals has been northwesterly at an average velocity of 22 knots. The predicted set and drift of the rotary current are 125° at 0.6 knot. What current should you expect?


32: The datum used for soundings on charts of the Atlantic Coast of the United States is mean __________.


46: What wind reverses directions seasonally?

    Y a. Monsoon winds
    N b. Hooked trades
    N c. Jet stream
    N d. Secondary winds

80: When the moon is at first quarter or third quarter phase, what type of tides will occur?

    N a. Apogean
    N b. Perigean
    Y c. Neap
    N d. Spring

131: A vertically-striped buoy may be __________.

    N a. striped black and green
    N b. striped black and yellow
    N c. lighted with a red light
    Y d. lighted with a white light

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

178: You are steering a southerly course, and you note that the chart predicts an easterly current. Without considering wind, how may you allow for the set?

    Y a. Head your vessel slightly to the right
    N b. Head your vessel slightly to the left
    N c. Decrease your speed
    N d. Increase your speed

185: A ship is in longitude 54°00'W on a true course of 270°. The ship's clocks are on the proper time zone. At what longitude should the clocks be changed to maintain the proper zone time?

    N a. 45°00'W
    N b. 52°30'W
    N c. 60°00'W
    Y d. 67°30'W

191: Safe water buoys may show ONLY __________.

    N a. flashing red lights
    N b. flashing green lights
    Y c. white lights
    N d. yellow lights

216: The prevailing winds in the band of latitude from approximately 5°N to 30°N are the __________.

    N a. prevailing westerlies
    Y b. northeast trade winds
    N c. southeast trade winds
    N d. doldrums

366: If an observer in the Northern Hemisphere faces the surface wind, the center of low pressure is to his______________.

    N a. left, slightly behind him
    Y b. right, slightly behind him
    N c. left, slightly in front of him
    N d. right, slightly in front of him

429: A great circle crosses the equator at 127°W. It will also cross the equator at what other longitude?

    N a. 127°E
    Y b. 53°E
    N c. 27°E
    N d. 27°W

472: Which conic projection chart features straight lines which closely approximate a great circle?

    N a. Polyconic
    Y b. Lambert conformal
    N c. Orthographic
    N d. Stereographic

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

582: Distance along a track line is measured on a Mercator chart by using the __________.

    Y a. latitude scale near the middle of the track line
    N b. longitude scale near the middle of the track line
    N c. latitude scale at the mid-latitude of the chart
    N d. latitude or longitude scale at the middle of the scale

606: Early indications of the approach of a hurricane may be all of the following EXCEPT __________.

    Y a. short confused swells
    N b. gradually increasing white clouds (mare's tails)
    N c. pumping barometer
    N d. continuous fine mist-like rain

723: If there is any doubt as to the proper operation of a radar, which statement is TRUE?

    N a. Only a radar expert can determine if the radar is operating.
    N b. All radars have indicator lights and alarms to signal improper operation.
    Y c. A radar range compared to the actual range of a known object can be used to check the operation of the radar.
    N d. The radar resolution detector must be energized to check the radar.

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

798: A HYDROLANT warning would normally be sent for all of the following EXCEPT __________.

    Y a. extinguishment of Robbins Reef Light in New York City's Upper Bay
    N b. unexploded ordinance in ocean waters at a depth of 78 fathoms (143 meters)
    N c. the presence of a large unwieldy tow in congested offshore water
    N d. a report of an overdue ship

800: You are to sail from Elizabethport, NJ, on 17 November 1983 with a maximum draft of 27 feet. You will pass over an obstruction in the channel near Sandy Hook that has a charted depth of 26 feet. The steaming time from Elizabethport to the obstruction is 1h 50m. What is the earliest time (ZD +5) you can sail on 17 November and pass over the obstruction with 2 feet of clearance?

    Y a. 0056
    N b. 0124
    N c. 0154
    N d. 0218

883: When changing from a compass course to a true course you should apply __________.

    N a. variation
    N b. deviation
    Y c. variation and deviation
    N d. a correction for the direction of current set

1066: The slope of a warm front is about __________.

    N a. 1 mile vertically to 10 miles horizontally
    N b. 1 mile vertically to 50 miles horizontally
    Y c. 1 mile vertically to 150 miles horizontally
    N d. 1 mile vertically to 500 miles horizontally

1116: When a cold air mass and a warm air mass meet, and there is no horizontal motion of either air mass, it is called a(n) __________.

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

1126: When a warm air mass is adjacent to a cold air mass, the separation line between the two is called a(n) __________.

    Y a. front
    N b. isobar
    N c. isotherm
    N d. equipotential line

1163: The total magnetic effects which cause deviation of a vessel's compass can be broken down into a series of components which are referred to as __________.

    N a. divisional parts
    Y b. coefficients
    N c. fractional parts
    N d. equations

1229: The initial great circle course angle between LAT 23°00'S, LONG 42°00'W and LAT 34°00'S, LONG 18°00'E is 063.8°. What is the true course?

    N a. 063.8°T
    Y b. 116.2°T
    N c. 243.8°T
    N d. 296.2°T

1267: What will be the velocity of the tidal current at Coxsackie, NY, at 0945 EST (ZD +5) on 11 March 1983?

    N a. 0.3 knot
    Y b. 0.7 knot
    N c. 1.2 knots
    N d. 1.9 knots

1281: The time required for a lighted aid to complete a full cycle of light changes is listed in the Light List as the __________.

    N a. set
    N b. frequency
    Y c. period
    N d. function

1365: The same side of the Moon is always toward the Earth, but more than half of its surface has been seen due to libration. Libration in latitude occurs because __________.

    Y a. the axis of rotation is tilted about 6.5° to the axis of revolution
    N b. the speed of revolution varies, while the rotational speed is essentially constant
    N c. of the rotational oscillation of the Moon with respect to its radius vector
    N d. of augmentation

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

1445: The planet Mars will have its greatest magnitude when at __________.

    N a. conjunction
    Y b. opposition
    N c. east quadrature
    N d. west quadrature

1446: When compared to air temperature, which factor is most useful in predicting fog?

    N a. Vapor pressure
    Y b. Dew point
    N c. Barometric pressure
    N d. Absolute humidity

1455: Inferior conjunction is possible for __________.

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

1489: Cumulonimbus clouds can produce __________.

    N a. dense fog and high humidity
    Y b. gusty winds, thunder, rain or hail, and lightning
    N c. clear skies with the approach of a cold front
    N d. a rapid drop in barometric pressure followed by darkness

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

1718: A hurricane is characterized by winds of __________.

    N a. up to 33 knots
    N b. 34 to 47 knots
    N c. 48 to 63 knots
    Y d. 64 knots or greater

1751: A tsunami is caused by a(n) __________.

    N a. tidal wave
    N b. storm surge caused by a hurricane or tropical storm
    Y c. earthquake on the ocean's floor
    N d. tornado

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

1850: A vessel heading WNW is on a course of __________.

    N a. 270.0°
    Y b. 292.5°
    N c. 315.0°
    N d. 337.5°

1946: When making landfall at night, you can determine if a light is a major light or an offshore buoy by __________.

    N a. the intensity of the light
    Y b. checking the period and characteristics against the Light List
    N c. the color, because the buoy will have only a red or a green light
    N d. Any of the above can be used to identify the light.

1950: The error in a sextant altitude caused by refraction is greatest when the celestial body is __________.

    N a. high in the sky
    Y b. near the horizon
    N c. rising
    N d. at or near transit

2001: You have changed course and steadied up on a range. Your heading is 285°T, same as the charted range, and it appears as in illustration D048NG. After several minutes the range appears as in illustration D047NG and your heading is still 285°T. This indicates a __________. (D047NG )

    N a. south-setting current
    Y b. north-setting current
    N c. leeway caused by a NE'ly wind
    N d. course made good to the left of the DR track

2174: By convention, the Earth's north magnetic pole is colored __________.

    N a. red
    N b. white
    Y c. blue
    N d. black

2232: A vessel is heading magnetic north and its magnetic compass indicates a heading of 003°. Which action should be taken to remove this error during compass adjustment?

    N a. If the red ends are to starboard you should raise the athwartships tray.
    Y b. If the red ends are to starboard, and the athwartships tray is at the bottom, you should remove some magnets.
    N c. If the red ends are to port, and the athwartships tray is at the top, you should reverse the magnets.
    N d. If the red ends are to port, and the athwartships tray is at the top, you should lower the tray.

2270: The lubber's line of a magnetic compass __________.

    N a. always shows true north direction
    Y b. indicates the vessel's heading
    N c. is always parallel to the vessel's transom
    N d. is located on the compass card

2290: Magnets in the binnacles of magnetic compasses are used to reduce the effect of __________.

    Y a. deviation
    N b. variation
    N c. local attraction
    N d. All of the above

2299: What condition exists at apogee?

    N a. The Earth is closest to the Sun.
    N b. The Moon is farthest from the Sun.
    Y c. The Earth is farthest from the Moon.
    N d. The Moon is between the Earth and the Sun.

2318: Miaplacidus is found in what constellation?

    N a. Puppis
    N b. Hydrus
    N c. Centaurus
    Y d. Carina

2416: An orange and white buoy indicating a vessel-exclusion area will be marked with what symbol?

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

2416: An orange and white buoy indicating a vessel-exclusion area will be marked with what symbol?

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

2479: The equation of time measures the __________.

    N a. difference between local apparent time and Greenwich apparent time
    N b. longitude in time units
    N c. difference between sidereal time and local time at the Greenwich meridian
    Y d. time between the passage of the mean sun and the apparent sun over a meridian

2539: Under the IALA cardinal system, a mark with quick white light showing 3 flashes every 10 seconds indicates that the safest water in the area is on the __________.

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

2656: What is the equivalent of 0 min. 16 sec. in arc units?

    N a. 0°32'
    N b. 0°16'
    Y c. 0°04'
    N d. 0°01'

2679: Under the U.S. Aids to Navigation System on the Western Rivers, a daymark on the right descending bank will __________.

    Y a. be green
    N b. have an odd number
    N c. indicate the gage reading
    N d. have yellow retroreflective markings

2924: You take a bearing of 264° of a lighthouse. What bearing of another object would give the best fix?

    N a. 289°
    Y b. 350v
    N c. 081°
    N d. 120°

2937: The depth of the water is indicated on a chart as 32 meters. This is equal to __________.

    N a. 11.50 fathoms
    N b. 12.62 fathoms
    Y c. 17.50 fathoms
    N d. 104.99 fathoms

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

3112: With respect to automatic identification systems (AIS) which of the following information is broadcast every one to ten seconds?

    N a. Vessel's draft
    N b. Air Draft
    Y c. Navigational status
    N d. Dimensions of vessel