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.


29: You are approaching a multiple-span bridge at night. The main navigational channel span will be indicated by __________.


126: A katabatic wind blows __________.


301: In the U.S. Aids to Navigation System, lateral aids as seen entering from seaward will display lights with which characteristic?


414: The barometer is an instrument for measuring the __________.

    N a. temperature
    N b. relative humidity
    N c. dew point
    Y d. atmospheric pressure

424: For an accurate barometer check, you would __________.

    N a. check it with a barometer on another vessel
    N b. take readings from several barometers and average them
    N c. check it with the barometer at the ship chandlery
    Y d. check it against radio or National Weather Service reports of the immediate vicinity

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.

577: Your vessel has a draft of 24 feet. On 7 April 1983 you wish to pass over a temporary obstruction near Lovell Island, MA, that has a charted depth of 22 feet. Allowing for a safety margin of 3.1 feet under your keel, what is the earliest time after 0100 EST (ZD +5) that this passage can be made?

    N a. 0248
    N b. 0304
    Y c. 0342
    N d. 0356

598: A great circle crosses the equator at 141E. It will also cross the equator at what other longitude?

    N a. 180E
    N b. 41E
    N c. 141W
    Y d. 39W

630: What kind of weather would you expect to accompany the passage of a tropical wave?

    Y a. Heavy rain and cloudiness
    N b. Good weather
    N c. A tropical storm
    N d. Dense fog

645: The arc of an hour circle between the celestial equator and a point on the celestial sphere, measured northward or southward through 90, is the __________.

    N a. altitude
    Y b. declination
    N c. latitude
    N d. azimuth angle

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

718: You are to sail from Elizabethport, NJ, on 22 May 1983 with a maximum draft of 28 feet. You will pass over an obstruction in the channel near Sandy Hook that has a charted depth of 27 feet. The steaming time from Elizabethport to the obstruction is 1h 40m. What is the earliest time (ZD +4) you can sail on the afternoon of 22 May and pass over the obstruction with 3 feet of clearance?

    Y a. 1407
    N b. 1331
    N c. 1303
    N d. 1242

726: Atmospheric pressure at sea level is equal to __________.

    N a. 14.7 pounds per square inch
    N b. 29.92 inches of mercury
    N c. 1013.25 millibars
    Y d. All of the above

749: You are enroute to assist vessel A. Vessel A is underway at 4.5 knots on course 233T, and bears 264T at 68 miles from you. What is the course to steer at 13 knots to intercept vessel A?

    N a. 249
    Y b. 256
    N c. 262
    N d. 268

816: Cyclones that have warm sectors usually move __________.

    N a. westerly
    Y b. parallel to the isobars in the warm sector
    N c. toward the nearest high pressure area
    N d. faster than the accompanying cold front

954: A thin, whitish, high cloud popularly known as "mares' tails" is __________.

    N a. altostratus
    N b. stratus
    N c. cumulus
    Y d. cirrus

961: In which country would you expect the channels to be marked with the IALA-B Buoyage System?

    Y a. Brazil
    N b. Tanzania
    N c. New Zealand
    N d. Norway

965: In order for a star to be used for a sight at lower transit, the star must __________.

    Y a. be circumpolar
    N b. have a declination equal to or greater than your latitude
    N c. have a GHA of 180
    N d. have the SHA equal to or less than the LHA

1083: Magnets are placed in horizontal trays in the compass binnacle to compensate for the __________.

    N a. induced magnetism in the vessel's horizontal soft iron
    N b. change in the magnetic field when the vessel inclines from vertical
    Y c. permanent magnetism of the vessel
    N d. magnetic fields caused by electrical currents in the vicinity

1176: After a cold front passes, the barometric pressure __________.

    N a. drops, and the temperature drops
    N b. drops, and the temperature rises
    Y c. rises, and the temperature drops
    N d. rises, and the temperature rises

1342: An occluded front on a weather map is colored __________.

    N a. blue line
    Y b. purple line
    N c. dashed blue line
    N d. alternate red and blue line

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

1402: As a vessel changes course to starboard, the compass card in a magnetic compass __________.

    N a. first turns to starboard then counterclockwise to port
    N b. also turns to starboard
    N c. turns counterclockwise to port
    Y d. remains aligned with compass north

1409: You are enroute to assist vessel A. Vessel A is underway at 5.5 knots on course 033T, and bears 284T, 43 miles from you. What is the time to intercept if you make 16 knots?

    N a. 2h 16m
    N b. 2h 22m
    Y c. 2h 34m
    N d. 2h 42m

1418: Static on your AM radio may be __________.

    Y a. an indication of nearby thunderstorm activity
    N b. an indication of "clearing" weather
    N c. of no meteorological significance
    N d. a sign of strong winds

1424: Except for N-S courses, and E-W courses on the equator, a great circle track between two points, when compared to a rhumb line track between the same two points, will __________.

    N a. always be nearer to the equator
    Y b. always be nearer to the elevated pole
    N c. be nearer to the pole in the Northern Hemisphere and nearer to the equator in the Southern Hemisphere
    N d. be nearer to the pole or the equator depending on the latitudes of the arrival and departure positions

1432: What benefit is a weather bulletin to a mariner?

    N a. It provides a legal reason to cancel a projected voyage.
    N b. It allows the mariner to make long term weather forecasts.
    N c. It is of little benefit since the weather changes frequently and rapidly.
    Y d. It gives the mariner time to prepare for weather changes.

1474: You are on course 061T. To check the longitude of your vessel you should observe a celestial body on which bearing?

    Y a. 090
    N b. 180
    N c. 241
    N d. 061

1519: You are preparing a weather report form, WS Form B-80. Your position is LAT 1038'S, LONG 0014'E. How would this be encoded? (D041NG )

    N a. LAT 10.6S, LONG 00.2E
    N b. L106S, 30002
    N c. 10385, 0014E
    Y d. 99106, 30002

1529: Widely spaced isobars on a weather map indicate __________.

    N a. high winds
    Y b. gentle breezes
    N c. ice, snow or frozen rain
    N d. probability of tornados

1542: To find a magnetic course from a true course you must apply __________.

    N a. magnetic anomalies (local disturbances)
    N b. deviation
    Y c. variation
    N d. deviation and variation

1560: Under the IALA-A and B Buoyage Systems, a buoy with alternating red and white vertical stripes indicates __________.

    Y a. that there is navigable water all around
    N b. an isolated danger exists
    N c. that the preferred channel is to port
    N d. that the preferred channel is to starboard

1565: Determine the approximate geographic visibility of an object, with a height above the water of 85 feet (25.9 meters), for an observer with a height of eye of 60 feet (18.3 meters).

    N a. 18.4 nm
    Y b. 19.9 nm
    N c. 20.8 nm
    N d. 21.5 nm

1599: The time interval between successive wave crests is called the __________.

    N a. trough
    Y b. period
    N c. frequency
    N d. epoch

1663: What is the primary source of the earth's weather?

    N a. The oceans
    N b. The moon
    Y c. The sun
    N d. The solar system

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

1952: 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
    Y b. Geocentric libration
    N c. Diurnal libration
    N d. Physical libration

1952: 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
    Y b. Geocentric libration
    N c. Diurnal libration
    N d. Physical libration

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

2054: The diagram is of a fixed C of E lock and dam. What navigational light(s) is(are) exhibited at the position indicated by the letter B? (D038NG )

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

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

2160: Information for updating nautical charts is primarily found in the __________.

    Y a. Notice to Mariners
    N b. Coast Pilots
    N c. nautical chart catalogs
    N d. Sailing Directions

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

2386: The path that the Sun appears to take among the stars is the __________.

    N a. zodiac
    N b. Tropic of Cancer in the Northern Hemisphere
    Y c. ecliptic
    N d. line of apsides

2480: You are on course 277T and take a relative bearing of a lighthouse of 045. What is the true bearing to the lighthouse?

    N a. 038
    N b. 232
    N c. 315
    Y d. 322

2520: When correcting the sextant altitude to apparent altitude you are correcting for inaccuracies in the reference level and __________.

    N a. the equivalent reading to the center of the body
    N b. the equivalent reading from the center of the Earth
    Y c. for inaccuracies in the instrument
    N d. the bending of the rays of light from the body

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

2609: The letter A in illustration D006NG represents the __________. (D006NG )

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

2668: You are approaching a drawbridge and have sounded the request-for-opening signal. The bridge has responded with five short blasts. What reply should you sound?

    N a. None; No reply is required
    Y b. Five short blasts
    N c. Two prolonged blasts
    N d. One prolonged, one short blast

2722: The paths of intended travel between three or more points is the __________.

    N a. course
    Y b. track
    N c. bearing
    N d. course over the ground

2750: When pushing a tow and approaching barges tied off to the shore, you should __________.

    N a. increase speed so you will pass faster
    Y b. decrease speed while passing so you won't create a suction
    N c. do nothing different as the barges should be tied off properly
    N d. move to the opposite side of the channel from the barges and increase speed

2816: The length of a wave is the length __________.

    N a. of the wave's crest
    N b. of the wave's trough
    N c. measured from crest to trough
    Y d. measured from crest to crest

2838: You take a bearing of 191 and 313 to two objects. Which bearing of a third object will give the best fix?

    N a. 001
    Y b. 069
    N c. 209
    N d. 356

2929: On 29 June 1981 you observe a back sight of the lower limb of the Moon. The sextant altitude (hs) is 11416.9'. The height of eye is 36 feet and the index error is 2.0' on the arc. The horizontal parallax is 60.5'. What is the observed altitude (Ho)?

    Y a. 6631.6'
    N b. 6631.0'
    N c. 6628.8'
    N d. 6626.0'

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

2965: Which symbol represents a 10-fathom curve?

    N a. ____ ____ ____
    N b. ... ____ ... ____
    Y c. ____ . _____ . ____ . ____
    N d. ........

3005: The agonic line on an isomagnetic chart indicates the __________.

    N a. magnetic equator
    N b. magnetic longitude reference line
    Y c. points where there is no variation
    N d. points where there is no annual change in variation

3074: ECDIS must give an alarm for which of the following cases?

    N a. When the speed of a dangerous target exceeds a set limit
    Y b. When the specified limit for deviation from the planned route is exceeded
    N c. If the ship's ETA has changed beyond the set limit
    N d. None of the above

3101: The typical operating range of automatic identification systems (AIS) at sea is nominally __________.

    N a. 2 nm
    N b. 8 nm
    Y c. 20 nm
    N d. 40 nm

3118: With respect to automatic identification systems (AIS), which information is required to be broadcast every 1 to 10 seconds?

    N a. Call sign and IMO number
    Y b. Course over ground and MMSI
    N c. MMSI number and call sign
    N d. Route Plan and navigational status