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.


4: Gyrocompass repeaters reproduce the indications of the master gyrocompass. They are __________.


9: When displayed under a single-span fixed bridge, red lights indicate __________.


50: The difference between the heights of low and high tide is the __________.


60: The predicted time that the ebb begins at the entrance to Delaware Bay is 1526. You are anchored off Chestnut St. in Philadelphia. If you get underway bound for sea at 1630 and turn for 12 knots, at what point will you lose the flood current?

    Y a. New Castle
    N b. Reedy Island
    N c. Mile 44
    N d. Ship John Shoal Lt.

83: All Loran-C transmitting stations are equipped with cesium frequency standards which permit __________.

    N a. every station in one chain to transmit at the same time
    Y b. each station to transmit without reference to another station
    N c. on-line transmission of single-line transmitters at the same time
    N d. each station to only depend on the master for synchronization and signal ratio

85: Your longitude is 179°59'W. The LMT at this longitude is 23h 56m of the 4th day of the month. Six minutes later your position is 179°59'E longitude. Your LMT and date is now __________.

    N a. 00h 02m on the 4th
    N b. 00h 02m on the 5th
    N c. 23h 50m on the 5th
    Y d. 00h 02m on the 6th

118: What describes an accurate position that is NOT based on any prior position?

    N a. Dead-reckoning position
    N b. Estimated position
    Y c. Fix
    N d. Running fix

133: The line connecting the Loran-C master station with a secondary station is called the __________.

    N a. focus line
    Y b. base line
    N c. side line
    N d. center line

192: The description "Racon" beside an illustration on a chart would mean a __________.

    N a. radar conspicuous beacon
    N b. circular radio beacon
    Y c. radar transponder beacon
    N d. radar calibration beacon

255: On March 17, at 0500 zone time, you cross the 180th meridian steaming eastward to west longitude. What is your local time?

    N a. You are in -12 time zone.
    N b. It is 1700, March 18.
    Y c. It is 0500, March 16.
    N d. It is 0500, March 18.

277: Your vessel goes aground in soft mud. You would have the best chance of refloating it on the next tide if it grounded at __________.

    N a. low water neap
    Y b. low water spring
    N c. high water neap
    N d. high water spring

329: The symbols shown are used on radio facsimile weather charts. Which symbol indicates a weather boundary? (D042NG )

    N a. I
    N b. H
    N c. G
    Y d. F

341: Buoys which only mark the left or right side of the channel will never exhibit a light with which characteristic?

    N a. Flashing
    N b. Quick flashing
    Y c. Composite group flashing
    N d. Equal interval (isophase)

349: The direction of the southeast trade winds is a result of the __________.

    N a. equatorial current
    N b. humidity
    Y c. rotation of the earth
    N d. change of seasons

388: You are underway on course 120°T and your maximum speed is 12 knots. The eye of a hurricane bears 150°T, 120 miles from your position. The hurricane is moving towards 295°T at 20 knots. If you maneuver at 12 knots to avoid the hurricane, what could be the maximum CPA?

    N a. 89 miles
    N b. 96 miles
    N c. 105 miles
    Y d. 117 miles

462: For what purpose would using a Lambert conformal chart be more convenient than using a Mercator?

    Y a. Plotting radio bearings over a long distance
    N b. Determining latitude and longitude of a fix
    N c. Measuring rhumb line distances
    N d. Measuring rhumb line directions

497: What will be the time after 0300 (ZD +4), on 5 March 1983, when the height of the tide at Port of Spain, Trinidad, will be 2.5 feet (.76 meters) ?

    N a. 0548
    Y b. 0602
    N c. 0618
    N d. 0634

502: A gnomonic projection is based on a(n) __________.

    Y a. plane tangent at one point
    N b. cylinder tangent at the equator
    N c. cone tangent at one parallel
    N d. infinite series of cones tangent at selected parallels

532: In a river subject to tidal currents, the best time to dock a ship without the assistance of tugs is __________.

    N a. at high water
    Y b. at slack water
    N c. at flood tide
    N d. when there is a following current

730: In the Northern Hemisphere, the largest waves or swells created by a typhoon or hurricane will be located __________.

    N a. in the southeast quadrant of the storm
    N b. directly behind the storm center
    Y c. forward and to the right of its course
    N d. behind and to the left of its course

764: Magnetic variation changes with a change in __________.

    N a. the vessel's heading
    N b. sea conditions
    N c. seasons
    Y d. the vessel's position

814: Steam smoke will occur when __________.

    Y a. extremely cold air from shore passes over warmer water
    N b. warm dry air from shore passes over cooler water
    N c. cold ocean water evaporates into warm air
    N d. cool rain passes through a warm air mass

861: You would expect to find channels marked with the IALA-A Buoyage System in __________.

    N a. Argentina
    N b. Japan
    Y c. India
    N d. Canada

908: From LAT 07°12'N, LONG 80°00'W, to LAT 47°12'S, LONG 169°18'E, the initial great circle course angle is 137.25°. How would you name this course?

    N a. N 137.25°E
    N b. S 137.25°E
    Y c. N 137.25°W
    N d. S 137.25°W

920: What is the average speed of the movement of a hurricane following the recurvature of its track?

    N a. 5 to 10 knots
    Y b. 20 to 30 knots
    N c. 40 to 50 knots
    N d. Over 60 knots

952: What is TRUE concerning new editions of Light Lists?

    N a. Supplements to new editions are issued monthly by the U.S. Coast Guard.
    N b. New editions are published by the National Ocean Service.
    Y c. New editions are corrected through the date shown on the title page.
    N d. None of the above

1124: The region containing 3/4 of the mass of the atmosphere and the region to which are confined such phenomena as clouds, storms, precipitation and changing weather conditions is called __________.

    N a. stratosphere
    Y b. troposphere
    N c. stratopause
    N d. tropopause

1154: The speed at which an ocean wave system advances is called __________.

    N a. wave length
    N b. ripple length
    Y c. group velocity
    N d. wave velocity

1170: Which statement concerning the illustration is correct? (Soundings and heights are in meters) (D010NG )

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

1323: The magnetic compass error which changes with the geographical location of your vessel is called __________.

    N a. deviation
    Y b. variation
    N c. compensation
    N d. differentiation

1369: Which of the following is the most useful factor for predicting weather?

    N a. The present reading of the barometer
    N b. The previous reading of the barometer
    N c. The difference in the barometric readings within the past 24 hours
    Y d. The rate and direction of change of barometric readings

1391: When a light is first seen on the horizon it will disappear again if the height of eye is immediately lowered several feet. When the eye is raised to its former height the light will again be visible. This process is called __________.

    N a. checking a light
    N b. raising a light
    N c. obscuring a light
    Y d. bobbing a light

1412: The distance between the surface of the water and the tidal datum is the __________.

    N a. actual water depth
    N b. range of tide
    N c. charted depth
    Y d. height of tide

1452: When is the rhumb line distance the same as the great circle distance?

    N a. Course 090°T in high latitudes
    Y b. Course 180°T when you cross the equator
    N c. Course 045°T in low latitudes
    N d. The rhumb line distance is always longer than the great circle distance.

1496: In a microbarograph, the pen should be checked and the inkwell filled __________.

    Y a. each time the chart is changed
    N b. once per month
    N c. once per week
    N d. daily

1511: When within 300 miles of a named tropical storm or hurricane, it is standard practice to send weather reports every __________.

    N a. 8 hours
    N b. 6 hours
    Y c. 3 hours
    N d. hour

1532: The position labeled "E" was plotted because __________. (D051NG )

    Y a. a dead reckoning position is plotted for each speed change
    N b. a dead reckoning position is plotted within a half-hour of each course change
    N c. the position is a running fix
    N d. the vessel's position was fixed at 1145

1623: Which of the following statements is FALSE?

    N a. An anemometer measures wind speed.
    N b. A barometer measures atmospheric pressure.
    N c. A thermometer measures temperature.
    Y d. A psychrometer measures wind pressure.

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

1681: You can expect frontal activity when two air masses collide and __________.

    N a. their barometric pressures and temperatures are the same
    N b. there are differences in how they track along the jet stream
    N c. there are no significant differences between their temperatures and moisture content
    Y d. there are significant differences between the temperature of each air mass

1731: When your vessel is on or near the path of an approaching tropical storm the __________.

    N a. wind direction remains steady
    N b. wind speed increases
    N c. barometer falls
    Y d. All of the above

1746: Swells that have outrun the storm are produced in the __________.

    N a. left front quadrant
    Y b. right front quadrant
    N c. rear
    N d. directly ahead on the storms projected track

1750: Clearance gauges at bridges indicate __________.

    N a. the height of the tide
    N b. depth of water under the bridge
    N c. charted vertical clearance at mean low water
    Y d. distance from the water to low steel of the bridge

1871: A lighted buoy to be left to starboard, when entering a U.S. port from seaward, shall have a __________.

    N a. green light
    N b. white light
    Y c. red light
    N d. light characteristic of Morse (A)

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

2087: The Light List indicates that a light has a nominal range of 20 miles and is 52 feet (16 meters) high. If the visibility is 20 miles and your height of eye is 20 feet (6 meters), at what approximate distance will you sight the light?

    N a. 33.0 nm
    N b. 20.0 nm
    Y c. 13.5 nm
    N d. 8.5 nm

2130: You are underway and pass by a lighthouse. Its light, which was white since you first sighted it, changes to red. This means __________.

    N a. the light is characterized as alternately flashing
    N b. the lighthouse has lost power and has switched to emergency lighting
    N c. it is the identifying light characteristic of the lighthouse
    Y d. you have entered an area of shoal water or other hazard

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

2354: A vessel is heading magnetic east and its magnetic compass indicates a heading of 093°. What action should be taken to remove this error during compass adjustment?

    N a. If the blue ends of the magnets are to port you should raise the athwartships tray.
    N b. If the red ends of magnets are to port you should lower the athwartships tray.
    N c. If the red ends of the magnets are aft you should lower the fore-and-aft tray.
    Y d. If the blue ends of the magnets are forward you should raise the fore-and-aft tray.

2476: At meridian transit, the diagram used by a navigator to illustrate the angles involved is based on the __________.

    N a. celestial equator as observed from above the south celestial pole
    N b. celestial equator as observed from above the north celestial pole
    Y c. plane of the observer's meridian
    N d. plane of the Greenwich meridian

2612: The dividing meridian between zone descriptions -7 and -8 is __________.

    Y a. 112°30'E
    N b. 118°30'E
    N c. 120°00'E
    N d. 116°30'W

2675: When you are steering on a pair of range lights and find the upper light is in line above the lower light, you should __________.

    N a. come left
    Y b. continue on the present course
    N c. come right
    N d. wait until the lights are no longer in a vertical line

2809: The diurnal variation of pressure is not visible in the middle latitudes in winter because __________.

    Y a. it is masked by the pressure changes of moving weather systems
    N b. the decreased gravitational effect from the sun causes the variation to fade
    N c. the decreased average temperature is less than the critical temperature
    N d. the increased Coriolis force disperses the pressure variation

2836: The correction tables in the front of the Nautical Almanac for use with sun sights do NOT include the effects of __________.

    N a. mean refraction
    N b. parallax
    N c. semidiameter
    Y d. irradiation

2931: The vertical distance from the tidal datum to the level of the water is the __________.

    N a. range of tide
    Y b. height of tide
    N c. actual water depth
    N d. charted depth

2969: A red triangular daymark marks __________.

    N a. the centerline of a navigable channel
    Y b. the starboard side of a channel
    N c. a prominent object of navigational interest that has no lateral significance
    N d. an area of a channel where passing another vessel is permitted

3011: The survey information upon which a chart is based is found __________.

    N a. at the top center of the next line
    Y b. near the chart title
    N c. at the lower left corner
    N d. at any convenient location

3024: Given are the courses and speeds of 4 vessels. The navigator of which vessel would be required to know the actual time of meridian transit in order to take an accurate observation at LAN ?

    N a. C 018°T, Sp 6 knots
    N b. C 079°T, Sp 24 knots
    N c. C 101°T, Sp 7 knots
    Y d. C 349°T, Sp 25 knots

3076: An ECDIS is required to display which information?

    N a. Radar targets
    N b. ARPA vectors
    Y c. Hydrographic data
    N d. All of the above