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.


141: You are enroute to assist vessel A. Vessel A is underway at 6 knots on course 133°T, and bears 042°T, 105 miles from you. What is the time to intercept if you make 10 knots?


153: The line extending beyond the stations at A and B is referred to as the __________. (D004NG )


184: When the index and horizon mirrors of a properly adjusted sextant are at an angle of 45° to each other, the arc reads __________.


186: In the doldrums you will NOT have __________.

    N a. high relative humidity
    N b. frequent showers and thunderstorms
    Y c. steep pressure gradients
    N d. frequent calms

302: Which symbol represents a 20-fathom curve?

    Y a. -..-..-..-..-
    N b. - - - - - - - -
    N c. - - . - - . - - . - - .
    N d. - - - - - - - -

482: Which statement about a gnomonic chart is correct?

    N a. A rhumb line appears as a straight line.
    N b. Distance is measured at the mid-latitude of the track line.
    N c. Meridians appear as curved lines converging toward the nearer pole.
    Y d. Parallels, except the equator, appear as curved lines.

584: The correction(s) which must be applied to an aneroid barometer reading include(s) __________.

    Y a. height error
    N b. gravity error
    N c. temperature error
    N d. All of the above

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.

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

649: You are on course 226°T. In order to check the latitude of your vessel, you should observe a celestial body on which bearing?

    N a. 226°
    N b. 270°
    Y c. 000°
    N d. 026°

655: The equator is __________.

    Y a. the primary great circle of the Earth perpendicular to the axis
    N b. the line to which all celestial observations are reduced
    N c. the line from which a celestial body's altitude is measured
    N d. All of the above

716: Standard atmospheric pressure in inches of mercury is __________.

    N a. 30.00
    N b. 28.92
    Y c. 29.92
    N d. 29.00

737: What describes an ebb current?

    N a. Horizontal movement of the water away from the land following low tide
    N b. Horizontal movement of the water toward the land following low tide
    Y c. Horizontal movement of the water away from the land following high tide
    N d. Horizontal movement of the water toward the land following high tide

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.

775: A sidereal day is shorter than a solar day. This difference is due to __________.

    N a. irregularities in the daily rotational rate of the Sun
    N b. the space motion of the solar system
    N c. the precession of the equinoxes
    Y d. the use of different reference points

835: When taking stars, those bodies to the east and west will __________.

    Y a. change altitude rapidly
    N b. change altitude slowly
    N c. remain in an almost fixed position
    N d. appear to be moving in the plane of the horizon

844: A cloud of marked vertical development (often anvil-shaped) would be classified as __________.

    N a. cirrus
    N b. cirrocumulus
    N c. altocumulus
    Y d. cumulonimbus

870: Vessels should maintain a sharp lookout, especially during December through March, when navigating the right whale's only known calving grounds which lie off the coasts of __________.

    N a. Nova Scotia
    N b. Maine and Massachusetts
    Y c. Georgia and NE Florida
    N d. California and Mexico

890: If several navigational lights are visible at the same time, each one may be positively identified by checking all of the following EXCEPT what against the Light List?

    N a. Rhythm
    N b. Period
    Y c. Intensity
    N d. Color

940: What is the length of a nautical mile?

    Y a. 6,076 feet
    N b. 5,280 feet
    N c. 2,000 yards
    N d. 1,850 meters

941: While preparing to enter a Brazilian port, you see ahead a red and green horizontally-striped buoy. The upper band is red. What action should you take?

    N a. Alter course to leave the buoy to port.
    Y b. Alter course to leave the buoy to starboard.
    N c. Pass the buoy close aboard on either side.
    N d. Pass the buoy well clear on either side.

1050: The passing of a low pressure system can be determined by periodically checking the __________.

    N a. thermometer
    N b. hygrometer
    Y c. barometer
    N d. anemometer

1070: Chart legends which indicate a conspicuous landmark are printed in __________.

    N a. underlined letters
    Y b. capital letters
    N c. italics
    N d. boldface print

1108: Preferred channel buoys indicate the preferred channel to transit by __________.

    N a. odd or even numbers
    Y b. the color of their top band
    N c. the location of the buoy in the channel junction
    N d. the buoy's light rhythms

1156: When cold air displaces warm air you have a(n) __________.

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

1184: Your position X is at LAT 35°S. Which winds are you experiencing? (D009NG )

    Y a. Northeasterly
    N b. Northwesterly
    N c. Southeasterly
    N d. Southwesterly

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

1234: Which information does the outer ring of a compass rose on a nautical chart provide?

    N a. Variation
    Y b. True directions
    N c. Magnetic directions
    N d. Annual rate of variation change

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

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

1247: What is the predicted velocity of the tidal current 2 miles west of Southwest Ledge for 2330 DST (ZD +4) on 7 September 1983?

    Y a. 1.3 knots
    N b. 1.6 knots
    N c. 1.9 knots
    N d. 2.2 knots

1266: A line of clouds, sharp changes in wind direction, and squalls are most frequently associated with a(n) __________.

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

1343: Variation is a compass error that you __________.

    N a. can correct by adjusting the compass card
    N b. can correct by adjusting the compensating magnets
    N c. can correct by changing the vessel's heading
    Y d. cannot correct

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

1387: You will be entering the Mystic River in Connecticut. What is the current at the Highway Bridge at 1900 EST (ZD +5) on 24 January 1983?

    N a. 2.2 knots flooding
    N b. Slack water
    Y c. Slight ebb
    N d. 2.5 knots ebbing

1438: In the Northern Hemisphere you are caught in the dangerous semicircle of a storm with plenty of sea room available. The best course of action is to bring the wind on the __________.

    N a. port quarter and make as much headway as possible
    N b. starboard quarter and make as much headway as possible
    Y c. starboard bow and make as much headway as possible
    N d. port bow and make as much headway as possible

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

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

1688: Which type of front forms when a cold front overtakes and forces a warm front upwards?

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

1705: Two well-developed low pressure areas may be separated by a __________.

    N a. trough of higher pressure
    N b. hill of higher pressure
    Y c. ridge of higher pressure
    N d. valley of higher pressure

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.

1884: If a sound signal is emitted from the oscillator of a fathometer, and two seconds elapse before the returning signal is picked up, what depth of water is indicated?

    N a. 1648 fathoms
    N b. 1248 fathoms
    N c. 1048 fathoms
    Y d. 824 fathoms

1904: In the horizon system of coordinates what is equivalent to the parallels of declination of the celestial equator system?

    N a. Vertical circles
    Y b. Parallels of altitude
    N c. Zenith distance
    N d. Azimuth angle

1919: The nadir is the point on the celestial sphere that is __________.

    N a. 90° away from the zenith
    N b. over Greenwich
    N c. on the western horizon
    Y d. directly below the observer

1928: "Rotation" is the __________.

    N a. wobbling of the Earth about its axis
    N b. motion of bodies in the solar system relative to the stars
    N c. motion of a celestial body in its orbit
    Y d. spinning of a celestial body about its axis

1969: The precession of the equinoxes of the Earth is __________.

    N a. the gradual increase in the period of rotation caused by the effects of the Moon
    N b. the irregularity of the Earth's orbit caused by influences of the Sun and Moon
    N c. caused by the elliptical shape of the Earth's orbit
    Y d. similar to a top spinning with its axis tilted

2070: What is the relative bearing of an object on the port beam?

    N a. 045°
    N b. 090°
    N c. 180°
    Y d. 270°

2075: Information about major breakdowns, repairs, or other emergency operations with regard to weirs and (or) wicket dams, on the western rivers, may be obtained by consulting the __________.

    N a. Light List Vol. V
    N b. U.S. Coast Pilot
    Y c. Broadcast Notice to Mariners
    N d. Sailing Directions

2167: 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, what light(s) will be shown at B if the lock walls and piers are not awash?

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

2207: Yesterday your chronometer read 11h 59m 58s at the 1200 GMT time tick. Today your chronometer reads 12h 00m 00s at the 1200 time tick. What is the chronometer rate?

    N a. Nil
    N b. 12h
    Y c. +2s
    N d. -2s

2220: A dead reckoning (DR) plot __________.

    N a. must utilize magnetic courses
    N b. must take set and drift into account
    N c. should be replotted hourly
    Y d. should be started each time the vessel's position is fixed

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

2239: A flashing green light displayed at a single lock means that the lock is __________.

    Y a. ready for entrance
    N b. ready for entrance, but gates cannot be closed completely
    N c. being made ready for entrance
    N d. not ready for entrance

2252: The vertical angle between the horizontal and the magnetic line of force is the __________.

    N a. elevation
    N b. magnetic angle
    N c. vertical angle
    Y d. dip

2341: Which statement concerning illustration D010NG is correct? (Soundings and heights are in meters)

    N a. Maury Lightship swings about her anchor on a circle with a 21-meter diameter.
    N b. The position of the lightship is indicated by the center of the star on the symbol's mast.
    Y c. The sunken wreck southwest of Beito Island shows the hull or superstructure above the sounding datum.
    N d. There is a 12-meter deep hole inside the 5-meter curve just west of Beito Island.

2646: During daylight savings time the meridian used for determining the time is located farther __________.

    Y a. east
    N b. west
    N c. east in west longitude and west in east longitude
    N d. west in west longitude and east in east longitude

2666: The following boats are approaching a lock. Which has priority for locking?

    N a. An 85-foot yacht
    Y b. Corps of Engineer towboat running empty-headed
    N c. "Delta Queen" (passenger vessel)
    N d. An integrated chemical tow

2741: A general chart could have a scale of __________.

    Y a. 1:200,000
    N b. 1:1,000,000
    N c. 1:50,000
    N d. not more than 1:25,000

2889: On 29 June 1981 you observe a back sight of the upper limb of the Moon. The sextant altitude (hs) is 114°16.9'. The height of eye is 36 feet, and the index error is 2.0' off the arc. The horizontal parallax is 60.5'. What is the observed altitude (Ho)?

    N a. 66°23.8'
    N b. 66°04.4'
    N c. 66°00.4'
    Y d. 65°53.8'

2920: Navigation charts of the Upper Mississippi River are published by __________.

    N a. National Ocean Service
    N b. Lake Survey
    Y c. Corps of Engineers, U.S. Army
    N d. U.S. Coast Guard

3056: A position obtained by applying ONLY your vessel's course and speed to a known position is a __________.

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