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.


64: Mean lower low water is the reference plane used for __________.


250: Weather systems in the middle latitudes generally travel from __________.


336: You are steaming eastward in the North Atlantic in an extratropical cyclonic storm and the wind is dead ahead. According to the law of Buys Ballot, the center of the low pressure lies __________.


350: When making landfall at night, the light from a powerful lighthouse may sometimes be seen before the lantern breaks the horizon. This light is called the __________.

    N a. diffusion
    N b. backscatter
    Y c. loom
    N d. elevation

357: On 10 August 1983 you will dock near Days Point, Weehawken, on the Hudson River, at 1800 DST (ZD +4). The charted depth alongside the pier is 24 feet (7.3 meters). What will be the depth of water when you dock?

    N a. 23.5 feet (7.1 m)
    Y b. 23.9 feet (7.2 m)
    N c. 24.9 feet (7.5 m)
    N d. 26.3 feet (8.0 m)

444: A sylphon cell is a part of a __________.

    N a. maximum thermometer
    Y b. barograph
    N c. thermograph
    N d. hygrometer

449: You are enroute to assist vessel A. Vessel A is underway at 5 knots on course 063°T, and bears 136°T at 78 miles from you. What is the course to steer at 13 knots to intercept vessel A?

    N a. 340°
    N b. 295°
    N c. 158°
    Y d. 114°

481: A special mark (yellow buoy), if lighted, may exhibit which light rhythm?

    Y a. Flashing
    N b. Morse "A"
    N c. Equal interval
    N d. Occulting

503: You are approaching a light fitted with a RACON. The light may be identified on the radar by __________.

    N a. a dashed line running from the center of the scope to the light
    N b. an audible signal when the sweep crosses the light
    N c. a circle appearing on the scope surrounding the light
    Y d. a coded signal appearing on the same bearing at a greater range than the light

590: On 16 January 1981, you take a sight of a star. The sextant altitude (hs) is 4°33.0'. The temperature is -10°C, and the barometer reads 992 millibars. The height of eye is 42 feet. The index error is 1.9' off the arc. What is the observed altitude (Ho)?

    N a. 4°10.2'
    N b. 4°14.3'
    Y c. 4°17.0'
    N d. 4°24.1'

596: Which condition would NOT indicate the approach of a tropical storm?

    N a. Long, high swells
    N b. Cirrus clouds
    N c. Halos about the Sun or Moon
    Y d. Decrease in wind velocity

605: Which is NOT a side of the celestial navigational triangle?

    N a. Co-latitude
    N b. Zenith distance
    Y c. Altitude
    N d. Co-declination

608: In which voyage, between two points, is the rhumb line distance NOT approximately the same as the great circle distance?

    N a. The two points are in low latitudes in the same hemisphere.
    Y b. The two points are in high latitudes in the same hemisphere.
    N c. The two points are near the equator, but in different hemispheres.
    N d. One point is near the equator, one point is in a high latitude, and both are near the 180th meridian.

696: The diurnal pressure variation is most noticeable in the __________.

    N a. polar regions
    N b. horse latitudes
    N c. roaring forties
    Y d. doldrums

756: What is a common unit of measure for atmospheric pressure?

    N a. centimeters
    Y b. Inches
    N c. Degrees
    N d. Feet

799: In Region A of the IALA Buoyage System, when entering from seaward, the starboard side of a channel would be marked by a __________.

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

905: The Sun's center is coincident with the principal vertical circle when __________.

    Y a. in lower transit
    N b. the hour circle and prime vertical are coincident
    N c. the declination is zero degrees and the azimuth is exactly N 135°E
    N d. the declination is zero degrees and the azimuth is exactly N 135°W

935: The Light List shows that a navigational light has a nominal range of 5 miles and a height above water of 21 feet (6.4 meters). Your height of eye is 32 feet (9.8 meters) and the visibility is 1.0 mile. At what approximate range will you first sight the light?

    N a. 1.0 mile
    Y b. 1.5 miles
    N c. 5.0 miles
    N d. 11.7 miles

950: Where is the dangerous semicircle located on a hurricane in the Southern Hemisphere?

    Y a. To the left of the storm's track
    N b. To the right of the storm's track
    N c. In the high pressure area
    N d. On the south side

994: Which list of clouds is in sequence, from highest to lowest in the sky?

    N a. Altostratus, cirrostratus, stratus
    Y b. Cirrostratus, altostratus, stratus
    N c. Stratus, cirrostratus, altostratus
    N d. Altostratus, stratus, cirrostratus

1101: In the North Sea area, you sight a buoy showing an uninterrupted quick-flashing white light. Which of the four topmarks shown will this buoy be fitted with under the IALA Buoyage system? (D031NG )

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

1171: A light that has a light period shorter than its dark period is described as __________.

    Y a. flashing
    N b. pulsating
    N c. occulting
    N d. alternating

1254: Lighted white and orange buoys must show which color light?

    N a. Orange
    Y b. White
    N c. Red
    N d. Alternating yellow and white

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

1388: If you observe a rapid fall of barometric pressure you should __________.

    N a. call the Coast Guard to verify the change
    N b. know the barometer is not working properly
    N c. contact the NWS or a local radio station
    Y d. prepare for the onset of stormy weather with strong winds

1588: The letter D in illustration D006NG represents the __________.

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

1629: Air temperature varies with __________.

    N a. the altitude above sea level
    N b. the season of the year
    N c. the latitude or distance from the equator
    Y d. All of the above

1635: An isotherm is __________.

    N a. a line on a weather map connecting equal points of both temperature and pressure
    N b. an instrument that measures the climatological effects of temperature
    N c. a line connecting points of equal barometric pressure on a weather map
    Y d. a line connecting points of equal temperature on a weather map

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

1730: If you observe the point of cloud convergence shifting to the right and the "bar" of the storm appears to move along the horizon __________.

    Y a. the center of the storm will by-pass you
    N b. the storm will strike you on the starboard side
    N c. you are in the direct path of the storm and should take immediate steps to batten down loose gear
    N d. the storm is starting to break up

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

1779: The Light List indicates that a light has a nominal range of 14 miles and is 26 feet high. If the visibility is 14 miles and your height of eye is 20 feet, at which approximate distance will you sight the light?

    N a. 7.5 miles
    Y b. 11.2 miles
    N c. 14.0 miles
    N d. 18.1 miles

1988: The parallel of latitude at 23°27'N is the __________.

    Y a. Tropic of Cancer
    N b. Tropic of Capricorn
    N c. Arctic Circle
    N d. ecliptic

2006: What is the relative bearing of an object broad on the port beam?

    N a. 315°
    N b. 300°
    Y c. 270°
    N d. 235°

2093: Information about major breakdowns, repairs, or other emergency operations with regard to weirs and (or) wicket dams, on the western rivers, may be obtained from the __________.

    N a. Light List Vol. V
    N b. List of Lights
    Y c. Broadcast Notice to Mariners
    N d. Sailing Directions

2143: What lights would you see on the Illinois water way when any wickets of the dam or bear traps are open, or partially open, which may cause a set in the current conditions in the upper lock approach?

    Y a. Red over amber (yellow)
    N b. Green over amber (yellow)
    N c. Red over Green
    N d. Green over Red

2150: On a Mercator chart, 1 nautical mile is equal to __________.

    N a. 1 minute of longitude
    N b. 1 degree of longitude
    Y c. 1 minute of latitude
    N d. 1 degree of latitude

2187: The diagram 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 D if the lock walls and piers are not awash? (D037NG )

    N a. No lights
    N b. Three red lights
    N c. Two red lights
    Y d. One red lights

2238: A vessel is heading magnetic northwest and its magnetic compass indicates a heading of 312°. What action should be taken to remove this error during compass adjustment?

    N a. If the quadrantal spheres are all of the way out replace them with larger spheres.
    N b. If the quadrantal spheres are all of the way in replace them with larger spheres.
    Y c. If the quadrantal spheres are all of the way in, move the spheres out.
    N d. If the quadrantal spheres are all of the way out, move the spheres in.

2280: Which would influence a magnetic compass?

    N a. Electrical wiring
    N b. Iron pipe
    N c. Radio
    Y d. All of the above

2348: Under the IALA cardinal system, a mark with a quick light showing 9 flashes every 15 seconds indicates that the safest water is on the __________.

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

2466: On the Western Rivers, a vessel crossing a river must __________.

    N a. only keep out of the way of a power-driven vessel descending the river
    N b. keep out of the way of any vessel descending the river
    Y c. keep out of the way of a power-driven vessel ascending or descending the river
    N d. keep out of the way of any vessel ascending or descending the river

2470: You are on course 344°T and take a relative bearing of a lighthouse of 090°. What is the true bearing to the lighthouse?

    N a. 016°
    Y b. 074°
    N c. 254°
    N d. 270°

2518: In low latitudes, the full Moon will always rise at about __________.

    N a. sunrise
    N b. 1200 LMT
    Y c. sunset
    N d. 2400 LMT

2579: A phase correction may be applicable to correct the sextant altitude correction of __________.

    N a. any star
    N b. the Sun
    N c. third magnitude stars only
    Y d. some planets

2719: Under the U.S. Aids to Navigation System on the Western Rivers, passing daymarks on the right descending bank are __________.

    N a. red diamond-shaped panels with red reflector borders
    N b. red triangular-shaped panels with red reflector borders
    Y c. green square-shaped panels with green reflector borders
    N d. green triangular-shaped panels with green reflector borders

2752: A daymark used to indicate the safe water in a channel will have which of the shapes shown? (D045NG )

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

2764: You are in a channel inbound from sea. A daymark used to mark a channel junction when the preferred channel is to port will have the shape indicated by what letter in illustration D045NG?

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

2791: The letter B in illustration D006NG represents the __________.

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

2877: Class I and II private aids to navigation in or along navigable waters of the United States are listed in the __________.

    N a. Sailing Directions
    Y b. Light List
    N c. List of Private Aids
    N d. Aids to Navigation Manual

2880: While upbound through Memphis, the weather report on the TV news indicates that a cold front will cross western Kentucky and Tennessee the next morning. What weather should accompany this front?

    N a. Light, southerly winds; high humidity and possibly fog
    N b. Overcast with steady, light rain or drizzle
    Y c. Gusting winds shifting to the northwest with thunderstorms
    N d. Scattered clouds with light to moderate southeasterly winds and possibly fog

2892: The Light List indicates that a dayboard is a type NB. You should __________.

    N a. see a black triangle
    N b. look for another daymark forming a range
    Y c. expect a daymark of no lateral significance
    N d. check to enter the correct channel at the junction daymark

2927: The position labeled C, as shown, was plotted because __________. (D051NG )

    N a. the vessel's course changed from due North to due East
    Y b. running fixes are better estimates of true position than dead-reckoning positions
    N c. the vessel's speed changed
    N d. All of the above are correct

2944: The height of a wave is the vertical distance __________.

    N a. from the still water plane to the crest
    N b. from the still water plane to the trough
    Y c. from crest to trough
    N d. between water levels at one-quarter of the wave's length

3035: A major advantage of the NAVTEX system when compared to other systems is that __________.

    N a. the information can be received on an ordinary FM radio
    Y b. warnings are printed out for reading when convenient
    N c. broadcasts are at scheduled times
    N d. a low frequency band is used for long distance transmission

3054: In illustration D051NG, the position labeled C was plotted because __________.

    Y a. running fixes are better estimates of true position than dead-reckoning positions are
    N b. the vessel's course changed from due North to due East
    N c. the vessel's speed changed
    N d. All of the above are correct

3057: IN REGION A of the IALA Buoyage System, when entering from seaward, the starboard side of a channel would be marked by a __________.

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

3103: In general, on how many radio channels will an automatic identification system (AIS) operate?

    N a. 1
    Y b. 3
    N c. 4
    N d. 12

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

3127: Which of the following statements is TRUE regarding automatic identification systems (AIS) ?

    N a. AIS cannot be used to make passing arrangements because the system is not capable of this type of ship-to-ship communications.
    N b. AIS cannot be used to make passing arrangements because the ship-to-ship text messaging feature is for emergency use only.
    Y c. AIS can be used to make passing arrangements via ship-to-ship text messaging but a vessel operator is not relieved from the requirement to sound whistle signals or make arrangements via bridge-to-bridge radiotelephone.
    N d. AIS can be used to make passing arrangements via ship-to-ship text massaging thus relieving a vessel operator from making such arrangements via bridge-to-bridge radiotelephone or signaling intent to pass via whistle signals.