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.


51: In the U.S. Aids to Navigation System, red and green horizontally-banded buoys mark __________.


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


127: Mean low water is the average height of __________.


214: A sextant having an index error that is "on the arc" has a __________.

    N a. positive correction
    N b. dip error
    Y c. negative correction
    N d. semidiameter error

243: The loran lines drawn on navigation charts represent __________.

    Y a. ground waves
    N b. skywaves
    N c. either ground waves or skywaves interchangeably
    N d. an average between ground wave and skywave positions

254: The range of tide is the __________.

    Y a. difference between the heights of high and low tide
    N b. distance the tide moves out from the shore
    N c. duration of time between high and low tide
    N d. maximum depth of the water at high tide

294: What is a nonadjustable error of the sextant?

    Y a. Prismatic error
    N b. Index error
    N c. Side error
    N d. Error of collimation

305: IN REGION A of the IALA Buoyage System, when entering from seaward, the port side of a channel would be marked by a __________.

    Y a. red can buoy
    N b. black can buoy
    N c. red conical buoy
    N d. black conical buoy

310: Which sextant shown has an index error of 3'30" off the arc? (D050NG )

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

347: The illustration shows the symbols used on radio facsimile weather charts. Which of these symbols indicates rain? (D042NG )

    Y a. N
    N b. M
    N c. I
    N d. G

426: The wind speed and direction observed from a moving vessel is known as __________.

    N a. coordinate wind
    N b. true wind
    Y c. apparent wind
    N d. anemometer wind

435: If an observer is at 35°N latitude, his zenith is __________.

    N a. 55°S of the celestial equator
    N b. at the north celestial pole
    Y c. 35°N of the celestial equator
    N d. 55°N of the celestial equator

564: A hygrometer is a device used for determining __________.

    N a. the absolute temperature
    N b. atmospheric pressure
    N c. wind velocity
    Y d. relative humidity

631: A light characteristic of composite group flashing indicates that there is a(n) __________.

    N a. sharp turn in the channel
    N b. narrowing in the channel at that point
    Y c. junction in the channel
    N d. obstruction that must be left to port

778: The navigable semicircle of a hurricane in the Northern Hemisphere is that area of the storm measured __________.

    N a. from true north clockwise to 180°T
    N b. from true north counterclockwise to 180°T
    N c. from the bow counterclockwise to 180° relative
    Y d. from the direction of the storm's movement counterclockwise 180°

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

820: A position obtained by crossing lines of position taken at different times and advanced to a common time is a(n) __________.

    N a. dead-reckoning position
    Y b. running fix
    N c. estimated position
    N d. fix

895: The ecliptic is __________.

    Y a. the path the Sun appears to take among the stars
    N b. the path the Earth appears to take among the stars
    N c. a diagram of the zodiac
    N d. a great circle on a gnomonic chart

904: All of the following are associated with cumulonimbus clouds EXCEPT __________.

    Y a. steady rainfall
    N b. hail storms
    N c. thunderstorms
    N d. tornadoes or waterspouts

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

1069: What do the numbers on isobars indicate?

    Y a. barometric pressure
    N b. temperature
    N c. rain in inches
    N d. wind speed

1186: As a cold front passes an observer, pressure __________.

    N a. drops and winds become variable
    Y b. rises and winds become gusty
    N c. drops and winds become gusty
    N d. rises and winds become variable

1241: Which picture shows a fixed and flashing light? (D034NG )

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

1304: The distance to the nearest vertex from any point on a great circle track cannot exceed __________.

    Y a. 5400 nautical miles
    N b. 5840 nautical miles
    N c. 6080 nautical miles
    N d. 10,800 nautical miles

1335: Plain language is usually used on marine weather __________.

    Y a. forecasts
    N b. observations
    N c. analyses
    N d. reports

1338: Which type of cloud is indicated by the number 6? (D039NG )

    N a. Altocumulus
    Y b. Stratocumulus
    N c. Altostratus
    N d. Cirrus

1374: On a working copy of a weather map, a warm front is represented by what color line?

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

1492: You are planning a voyage from San Francisco to Japan. Which publication contains information on the ocean routes?

    N a. Coast Pilot
    Y b. Sailing Directions (Planning Guide)
    N c. Sailing Directions (Enroute)
    N d. World Port Index

1540: You are sailing south on the Intracoastal Waterway (ICW) when you sight a green can buoy with a yellow square painted on it. Which of the following is TRUE?

    N a. You should pass the buoy close aboard on either side.
    N b. The buoy marks the end of the ICW in that area.
    Y c. You should leave the buoy to port.
    N d. The yellow square is retroreflective material used to assist in sighting the buoy at night.

1628: As the temperature of the air reaches the dew point, __________.

    N a. rain must develop
    Y b. fog may form
    N c. it begins to snow
    N d. water freezes

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

1665: Air circulation is caused or affected by __________.

    N a. the rotation of the earth on its axis
    N b. convection currents caused by differences in radiant heating between equatorial and polar regions
    N c. mountain ranges
    Y d. All 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

1711: An instrument that indicates wind direction is known as a(n) __________.

    Y a. weather vane, wind vane or wind sock
    N b. hydrometer
    N c. hygrometer
    N d. sling psychrometer

1733: An instrument which maintains a continuous record of temperature changes is called a __________.

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

1775: The letter A in illustration D006NG represents the __________.

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

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°

1956: In the North Sea area, you sight a buoy showing a quick white light with 6 flashes, followed by one long flash at 15 second intervals. Which of the four topmarks shown would be fitted to this buoy? (D030NG )

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

1976: The Moon is nearest to the Earth at __________.

    Y a. perigee
    N b. the vernal equinox
    N c. the new Moon
    N d. the full Moon

2061: Fog is likely to occur when there is little difference between the dew point and the __________.

    N a. relative humidity
    Y b. air temperature
    N c. barometric pressure
    N d. absolute humidity

2175: Diagram Number D037NG 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, which light(s) will be shown at D if the lock walls and piers are not awash?

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

2241: The letter C in illustration D006NG represents the __________.

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

2304: The Moon is subject to four types of libration. Which of the following is NOT one of these types of libration?

    N a. Libration in longitude
    N b. Diurnal libration
    Y c. Vertical libration
    N d. Libration in latitude

2351: A position obtained by applying ONLY your vessel's course and speed to a known position is a __________.

    N a. running fix
    N b. probable position
    N c. fix
    Y d. dead-reckoning position

2399: Which statement about the time diagram shown is TRUE? (D008NG )

    N a. The Greenwich date is one day later than your date.
    N b. The diagram is valid only if you are in the southern hemisphere.
    N c. The LHA of the Sun is approximately 40°.
    Y d. The diagram represents a morning Sun sight.

2460: You are on course 344°T and take a relative bearing of a lighthouse of 270°. What is the true bearing to the lighthouse?

    N a. 016°
    N b. 074°
    N c. 090°
    Y d. 254°

2474: A vessel is heading magnetic north and its magnetic compass indicates a heading of 356°. What action should be taken to remove this error during compass adjustment?

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

2482: When a vessel changes course from one cardinal heading to another cardinal heading while adjusting the compass, which action should be taken?

    N a. The course change should be made rapidly to prevent transient induced magnetism while passing the intercardinal headings.
    Y b. After the new heading is reached, the vessel should steam on that course for at least two minutes before the adjustment.
    N c. During the course change, you should gently tap the compass to remove any error caused by friction on the pivot bearing.
    N d. After steadying on the new heading, the compass card should be slewed by a magnet and allowed to oscillate freely to remove any gaussin error.

2514: Sidereal time is NOT used __________.

    N a. as the basis for star charts
    N b. to enter a star finder
    N c. in sight reduction using Pub 249
    Y d. in sight reductions of planet observations

2851: You determine your vessel's position by taking a range and bearing to a buoy. Your position will be plotted as a(n) __________.

    N a. dead-reckoning position
    Y b. estimated position
    N c. running fix
    N d. fix

2899: You take a bearing of 043° and 169° of two objects. What bearing of a third object will give the best fix?

    N a. 356°
    N b. 073°
    N c. 192°
    Y d. 309°

2936: Information on search and rescue procedures and special, local communications used in Mexican waters will be found in the __________.

    N a. World Port Index
    N b. International Code of Signals (Pub 102)
    Y c. Sailing Directions (Planning Guides)
    N d. International Aeronautical and Maritime Search and Rescue Manual

2958: Drawbridges equipped with radiotelephones display a __________.

    N a. day signal of a yellow diamond marked with the call sign
    N b. white sign with the number 16 and the call sign on it
    N c. black and white diamond marked with RT 16
    Y d. blue and white sign showing the radio's channels

2988: The buoy indicated by the letter A is a __________. (D044NG )

    N a. nun
    Y b. can
    N c. spar
    N d. pillar

3018: You take a bearing of 356° of a lighthouse. Which bearing of another object would give the best fix?

    N a. 013°
    N b. 178°
    Y c. 256°
    N d. 342°

3033: A navigator fixing a vessel's position by radar __________.

    Y a. can use radar information from one object to fix the position
    N b. should never use radar bearings
    N c. should only use radar bearings when the range exceeds the distance to the horizon
    N d. must use information from targets forward of the beam

3041: The letter H in illustration D006NG represents the __________.

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

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

3110: While underway, automatic identification systems (AIS) broadcast all of the following information every 1 to 10 seconds EXCEPT the __________.

    N a. speed over ground
    N b. latitude and longitude
    N c. course over ground
    Y d. ship's scantlings

3126: Which of the following statements is TRUE regarding automatic identification systems (AIS)?

    N a. AIS will not provide information on another vessel if that vessel is indistinguishable in radar sea clutter.
    N b. AIS can be relied upon as the sole means to determine risk of collision and safe speed.
    N c. AIS is designed to replace ARPA, maneuvering boards, and visual bearings as a means to ascertain the risk of collision.
    Y d. AIS provides the other vessel's identity, dimensions and navigational status regardless of visibility.