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.


84: When using an echo sounder in deep water, it is NOT unusual to __________.


105: If the GMT is 1500, the time at 75°E longitude is __________.


238: The predicted time that the flood 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 1430 and turn for 11 knots, at what point will you lose the ebb current?


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

    Y a. range
    N b. period
    N c. depth
    N d. distance

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

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

297: The tides in Boston Harbor generally __________.

    N a. are diurnal in nature
    N b. have their variations caused by the changing declination of the Moon
    Y c. have a greater range than the tides in Gulf Coast ports
    N d. All of the above

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

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

531: You have been informed that dredging operations may be underway in your vicinity. Which buoy indicates the dredging area?

    N a. White buoy with a green top
    N b. White and international orange buoy
    Y c. Yellow buoy
    N d. Yellow and black vertically-striped buoy

554: A sling psychrometer is a(n) __________.

    N a. type of cargo gear
    N b. instrument used in celestial navigation
    Y c. instrument used to measure relative humidity
    N d. instrument used to measure specific gravity

562: You wish to measure the distance on a Mercator chart between a point in latitude 42°30'N and a point in latitude 40°30'N. To measure 30 miles at a time you should set the points of the dividers at __________.

    Y a. 41°15' and 41°45'
    N b. 41°45' and 42°15'
    N c. 42°15' and 42°45'
    N d. 42°00' and 42°30'

580: On 21 January 1981, you observe a back sight of the Sun's lower limb. The sextant altitude (hs) is 121°31.5'. The index error is 2.5' on the arc. The height of eye is 31 feet (9.3 meters). What is the observed altitude (Ho)?

    N a. 31°06.2'
    Y b. 58°53.1'
    N c. 58°12.2'
    N d. 58°03.2'

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

    N a. 063°
    N b. 068°
    N c. 073°
    Y d. 079°

685: Thirty-two meters equals __________.

    N a. 17.50 feet
    N b. 58.52 feet
    N c. 96.00 feet
    Y d. 104.99 feet

711: In the IALA Maritime Buoyage System, a red and white vertically-striped buoy is used as a(n) __________.

    Y a. safe water mark
    N b. cardinal mark
    N c. isolated danger mark
    N d. special mark not primarily used for navigation

757: The term "flood current" refers to that time when the water __________.

    Y a. is flowing towards the land
    N b. is moving towards the ocean
    N c. level is not changing
    N d. level is rising because of heavy rains

767: What describes a flood current?

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

769: What does not contribute to the commercial GPS receiver position error?

    N a. Satellite clock
    Y b. Ship's speed
    N c. Atmospheric/Ionospheric propagation
    N d. Satellites' orbits

791: Under the IALA Buoyage Systems, the topmark of a red and white vertically-striped buoy shall be __________.

    N a. X-shaped
    N b. two black spheres
    Y c. a single red sphere
    N d. a single red cone

880: You are taking bearings on two known objects ashore. The BEST fix is obtained when the angle between the lines of position is __________.

    N a. 60°
    Y b. 90°
    N c. 45°
    N d. 30°

911: Under the IALA-B Buoyage System, a buoy displaying a red light will __________.

    Y a. be left to starboard when entering from seaward
    N b. show a light characteristic of Morse Code "A"
    N c. be lettered
    N d. have a radar reflector

972: In which source could you find the number of a chart for a certain geographic area?

    N a. Chart No. 1
    Y b. Catalog of Charts
    N c. American Practical Navigator
    N d. U.S. Coast Guard Light List

1014: Relative humidity is the percentage of water vapor that is in the air as compared to the maximum amount it can hold at __________.

    N a. a specific barometric pressure
    Y b. a specific temperature
    N c. a specific wind speed
    N d. any time

1063: When adjusting a magnetic compass using the fore-and-aft permanent magnets, you should __________.

    N a. use the magnets one at a time, putting one in one side and then one on the opposite side, one step higher.
    N b. use the magnets in pairs, starting at the top, with trays at the highest point of travel
    Y c. use the magnets in pairs, from the bottom up, with the trays at the lowest point of travel
    N d. fill all the trays with magnets, then remove them one-by-one until the deviation is removed

1071: A cardinal mark showing an uninterrupted quick-flashing white light indicates the deepest water in the area is on the __________.

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

1139: A star is observed at lower transit. The line of position derived from this sight is __________.

    N a. on the prime vertical
    Y b. a latitude line
    N c. a longitude line
    N d. of no special significance

1152: When using GPS without Selective Availability, you may expect your horizontal accuracy to be better than __________.

    N a. 3 meters
    Y b. 20 meters
    N c. 100 meters
    N d. 200 meters

1207: What will be the velocity of the tidal current at New London Harbor Entrance, CT, at 1615 EST (ZD +5) on 26 December 1983?

    Y a. 0.2 knot
    N b. 0.4 knot
    N c. 0.7 knot
    N d. 0.9 knot

1224: NGA (NIMA) charts are adopting the metric system. In order to change a charted depth in meters to feet you may use the conversion table found __________.

    N a. in the Light List
    N b. in Bowditch Vol. II
    N c. on the chart
    Y d. All of the above

1349: The symbols shown are used on radio facsimile weather charts. Which of these symbols indicates a severe squall line? (D042NG )

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

1404: A great circle will intersect the equator at how many degrees of longitude apart?

    N a. 0°
    N b. 45°
    N c. 90°
    Y d. 180°

1455: Inferior conjunction is possible for __________.

    Y a. Mercury
    N b. Saturn
    N c. Mars
    N d. Jupiter

1464: A line of position derived from a loran reading is a section of a(n) __________.

    N a. straight line
    N b. arc
    N c. parabola
    Y d. hyperbola

1469: The charted channel depth at Eastport, ME, is 28 feet. You are drawing 31.5 feet and wish 2 feet clearance under the keel. What is the earliest time after 1700 (ZD +4) on 6 September 1983 that you can enter the channel?

    N a. 1825
    N b. 1903
    Y c. 1915
    N d. 2003

1509: Your facsimile prognostic chart indicates that you will cross the cold front of a low pressure system in about 24 hours. You should __________.

    N a. expect to see cirrus clouds followed by altostratus and nimbostratus clouds
    N b. alter course to remain in the navigable semicircle
    Y c. prepare for gusty winds, thunderstorms, and a sudden wind shift
    N d. expect clear weather, with steady winds and pressure, until the front passes

1536: What will NOT induce errors into a Doppler sonar log?

    Y a. Increased draft
    N b. Pitch
    N c. Roll
    N d. Change in trim

1597: The dense black cumulonimbus clouds surrounding the eye of a hurricane are called __________.

    N a. spiral rainbands
    Y b. cloud walls
    N c. funnel clouds
    N d. cyclonic spirals

1689: The "horse latitudes" are regions of __________.

    N a. brisk prevailing winds
    Y b. light airs and calms
    N c. abundant blue sea grass vegetation
    N d. None of the above

1738: In the Northern Hemisphere, the right half of the storm is known as the dangerous semicircle because __________.

    N a. The wind speed is greater here since the wind is traveling in the same general direction as the storm's track
    N b. the direction of the wind and seas might carry a vessel into the path of the storm
    N c. the seas are higher because of greater wind speed
    Y d. All of the above

1858: A white buoy with an orange cross within a diamond marked on it indicates __________.

    N a. danger
    Y b. vessels are excluded from the area
    N c. an anchorage area
    N d. operating restrictions are in effect

1941: 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. red can buoy
    N b. red conical buoy
    N c. green can buoy
    Y d. green conical buoy

2021: While on watch, you notice that the air temperature is dropping and is approaching the dew point. Which type of weather should be forecasted?

    N a. Hail
    N b. Heavy rain
    N c. Sleet
    Y d. Fog

2112: Vessels regularly navigating rivers above Cairo, Illinois, shall at all times have on board a copy of __________.

    N a. U.S. Coast Pilot
    Y b. U.S. Army Corps of Engineers Regulations (Blue Book)
    N c. Nautical Almanac for the year
    N d. Light List Vol. V

2129: 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. No lights
    Y b. Three red lights
    N c. Two red lights
    N d. One red light

2190: Clouds are classified according to their __________.

    N a. size
    N b. moisture content
    Y c. altitude and how they were formed
    N d. location in a front

2214: By convention, the Earth's south magnetic pole is colored __________.

    N a. blue
    N b. black
    N c. white
    Y d. red

2232: A vessel is heading magnetic north and its magnetic compass indicates a heading of 003°. Which action should be taken to remove this error during compass adjustment?

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

2284: Bellatrix is found in what constellation?

    N a. Canis Minor
    N b. Gemini
    N c. Taurus
    Y d. Orion

2299: What condition exists at apogee?

    N a. The Earth is closest to the Sun.
    N b. The Moon is farthest from the Sun.
    Y c. The Earth is farthest from the Moon.
    N d. The Moon is between the Earth and the Sun.

2336: The period of revolution of the Moon is __________.

    N a. 24 hours
    Y b. about 27.3 days
    N c. 365 days
    N d. about 19 years

2373: The vertical distance from the tidal datum to the level of the water is the __________.

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

2436: Aphelion is the point where the Sun __________.

    N a. and Moon and Earth form a right angle
    N b. and Moon and Earth are in line
    N c. crosses the celestial equator
    Y d. is farthest from the Earth

2490: A vertex of the navigational triangle is NOT located at the __________.

    N a. elevated pole
    N b. celestial body
    N c. zenith
    Y d. coaltitude

2676: The place where a channel moves from along one bank of the river over to the other bank of the river is called a __________.

    N a. draft
    N b. cutoff
    N c. draw
    Y d. crossing

2690: Right ascension is primarily used by the navigator for __________.

    N a. calculating amplitudes
    N b. calculating great circle sailings by the Ageton method
    N c. entering the Air Navigation Tables (Selected Stars) Pub 249
    Y d. plotting on star finders

2710: In the horizon system of coordinates what is equivalent to the local hour angle of the celestial equator system?

    N a. Altitude
    Y b. Azimuth
    N c. Zenith distance
    N d. Colongitude

2782: Your radar is set on a true motion display. Which of the following will appear to move across the PPI scope.

    Y a. Own ship's marker
    N b. Echo from a ship at anchor
    N c. Echoes from land masses
    N d. All of the above

2870: Steam fog is most likely to occur on the Mississippi and Ohio Rivers in __________.

    N a. spring, around late evening
    N b. spring, around early evening
    Y c. fall, around early morning
    N d. fall, around midday

2989: On 13 November 1981 you observe a back sight of the lower limb of the Moon. The sextant altitude (hs) is 110°31.2'. The height of eye is 46 feet and the index error is 2.0' off the arc. The horizontal parallax is 61.3'. What is the observed altitude (Ho)?

    N a. 70°41.4
    N b. 70°15.4'
    Y c. 70°11.4'
    N d. 70°02.2

3040: Which instrument is used to predict the approach of a low pressure system?

    N a. Anemometer
    N b. Fathometer
    Y c. Barometer
    N d. Thermometer

3077: ECDIS must have the capability to preserve the record of the voyage track for the previous __________.

    N a. 4 hours
    N b. 6 hours
    Y c. 12 hours
    N d. 24 hours