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.


51: In the U.S. Aids to Navigation System, red and green horizontally-banded buoys mark __________.


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


76: In the Northern Hemisphere, a wind that shifts counterclockwise is a __________.


87: A tide is called diurnal when __________.

    Y a. only one high and one low water occur during a lunar day
    N b. the high tide is higher and the low tide is lower than usual
    N c. the high tide and low tide are exactly six hours apart
    N d. two high tides occur during a lunar day

114: All echo-sounders can measure the __________.

    N a. actual depth of water
    Y b. actual depth of water below keel
    N c. average depth from waterline to hard bottom
    N d. average depth of water to soft bottom

158: Discounting slip, if your vessel is turning RPM for 10 knots and making good a speed of 10 knots, the current could be __________.

    N a. with you at 10 knots
    N b. against you at 10 knots
    Y c. slack
    N d. with you at 2 knots

191: Safe water buoys may show ONLY __________.

    N a. flashing red lights
    N b. flashing green lights
    Y c. white lights
    N d. yellow lights

247: Neap tides occur __________.

    N a. at the start of spring, when the Sun is nearly over the equator
    N b. only when the Sun and Moon are on the same sides of the Earth and are nearly in line
    Y c. when the Sun and Moon are at approximately 90° to each other, as seen from the Earth
    N d. when the Sun, Moon, and Earth are nearly in line, regardless of alignment order

315: Which statement about the time diagram shown DO08NG is TRUE?

    N a. You are in west longitude.
    N b. Your date is ahead of Greenwich.
    Y c. The meridian angle of the Sun is east.
    N d. The GHA of the Sun is less than 180°.

337: To predict the actual depth of water using the Tide Tables, the number obtained from the Tide Tables is __________.

    N a. the actual depth
    Y b. added to or subtracted from the charted depth
    N c. multiplied by the charted depth
    N d. divided by the charted depth

337: To predict the actual depth of water using the Tide Tables, the number obtained from the Tide Tables is __________.

    N a. the actual depth
    Y b. added to or subtracted from the charted depth
    N c. multiplied by the charted depth
    N d. divided by the charted depth

363: Your dead reckoning position should be plotted __________.

    N a. whenever an estimated position is plotted
    N b. when it agrees with your loran position
    N c. when coming on or going off soundings
    Y d. at least every hour on the hour in the open waters of the sea

418: In most cases, the direction of the apparent wind lies between the bow and __________.

    Y a. the direction of the true wind
    N b. true north
    N c. the beam on the windward side
    N d. the beam on the lee side

442: In very high latitudes, the most practical chart projection is the __________.

    N a. Mercator
    N b. gnomonic
    N c. azimuthal
    Y d. Lambert conformal

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

801: You are entering an African port and see ahead of you a red can-shaped buoy. What action should you take?

    Y a. Alter course to leave the buoy to port
    N 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

837: The Brazil Current flows in which general direction?

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

853: The standard magnetic compass heading differs from the true heading by __________.

    Y a. compass error
    N b. latitude
    N c. variation
    N d. deviation

923: A magnetic compass card is marked in how many degrees?

    N a. 90
    N b. 180
    Y c. 360
    N d. 400

953: The magnetic compass operates on the principle that __________.

    N a. like magnetic poles attract
    N b. unlike magnetic poles repel
    Y c. unlike poles attract
    N d. the poles of the compass line up with the geographic poles of the earth

1064: The dew point temperature is __________.

    N a. always higher than the air temperature
    N b. always lower than the air temperature
    N c. equal to the difference between the wet and dry bulb temperatures
    Y d. the temperature at which the air is saturated with water vapor

1067: The two most effective generating forces of surface ocean currents are __________.

    N a. temperature and salinity differences in the water
    Y b. wind and density differences in the water
    N c. water depth and underwater topography
    N d. rotation of the Earth and continental interference

1069: What do the numbers on isobars indicate?

    Y a. barometric pressure
    N b. temperature
    N c. rain in inches
    N d. wind speed

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

1150: You are on course 312°T. To check the speed of your vessel you should observe a celestial body on which bearing?

    Y a. 312°
    N b. 000°
    N c. 090°
    N d. 222°

1185: An orange and white buoy with a rectangle on it displays __________.

    N a. directions
    N b. distances
    N c. locations
    Y d. All of the above

1191: You plot a fix using three lines of position and find they intersect in a triangle. The actual position of the vessel __________.

    N a. is outside of the triangle
    N b. may be anywhere in the triangle
    Y c. may be inside or outside of the triangle
    N d. is the geometric center of the triangle

1396: On the approach of a warm front the barometric pressure usually __________.

    Y a. falls
    N b. rises
    N c. is steady
    N d. is unreliable

1419: The MOST important feature of the material used for making the binnacle of a standard magnetic compass is that it is __________.

    Y a. nonmagnetic
    N b. weatherproof
    N c. corrosion resistant
    N d. capable of being permanently affixed to the vessel

1487: At the approaches to Savannah, GA, with the wind coming out of the west, the wind-driven current will be flowing approximately __________.

    Y a. 080°
    N b. 100°
    N c. 260°
    N d. 280°

1609: A rapid rise or fall of the barometer indicates __________.

    N a. heavy rain within six hours
    N b. a decrease in wind velocity
    Y c. a change in the present weather conditions
    N d. that fog will soon set in

1634: A lighted buoy to be left to starboard, when entering a U.S. port from seaward, shall have a __________.

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

1642: Which type of cloud formation should be of immediate concern to small craft operators?

    N a. cirrus
    N b. altostratus
    N c. nimbostratus
    Y d. cumulonimbus

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

1677: The position labeled "E" was plotted because __________. (D051NG )

    N a. a dead reckoning position is plotted within a half-hour of each course change
    Y b. a dead reckoning position is plotted for each speed change
    N c. the position is a running fix 1125
    N d. the vessel's position was fixed at 1145

1735: A vessel entering the eye of a hurricane should expect __________.

    N a. moderating winds and heavy confused seas to strike his vessel from all directions
    N b. the winds to increase to hurricane force and strike from a different direction as the eye passes
    N c. the barometer to reach the lowest point
    Y d. All of the above

1772: The GP of a body for a high altitude sight is determined from the declination and the __________.

    Y a. Greenwich hour angle
    N b. azimuth
    N c. zenith distance
    N d. right ascension

1827: The position labeled "D" was plotted because __________. (D051NG )

    N a. a dead reckoning position is plotted within 30 minutes of a running fix
    Y b. a dead reckoning position is plotted for each course change
    N c. the vessel's speed changed at 1125
    N d. All of the above

1899: What is the relative bearing of an object broad on the starboard beam?

    N a. 045°
    N b. 060°
    N c. 075°
    Y d. 090°

1987: An instrument useful in predicting fog is the __________.

    Y a. sling psychrometer
    N b. microbarograph
    N c. anemometer
    N d. aneroid barometer

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

2081: 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. 30°
    N b. 45°
    N c. 60°
    Y d. 90°

2104: A white buoy marked with an orange rectangle indicates __________.

    N a. mid-channel
    N b. a fish net area
    Y c. general information
    N d. an anchorage

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

2176: The illustration 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. Three red lights
    N b. Two red lights
    Y c. One red light
    N d. One amber light

2176: The illustration 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. Three red lights
    N b. Two red lights
    Y c. One red light
    N d. One amber light

2180: Relative humidity is defined as __________.

    N a. the maximum vapor content the air is capable of holding
    N b. the minimum vapor content the air is capable of holding
    Y c. the ratio of the actual vapor content at the current temperature to the air's vapor holding capability
    N d. the relation of the moisture content of the air to barometric pressure

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.

2243: Which aid is NOT marked on a chart with a magenta circle?

    N a. Radar station
    N b. Radar transponder beacon
    Y c. Aero light
    N d. Radio beacon

2334: Other than the Sun and Moon, the brightest object in the sky is __________.

    N a. Sirius
    N b. Canopus
    Y c. Venus
    N d. Jupiter

2464: Under the IALA-A Buoyage System, when entering from seaward a lateral system buoy to be left to port may display which topmark shown? (D046NG )

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

2569: The mean sun used to measure time moves __________.

    N a. along the ecliptic at 15° per hour
    N b. along the celestial equator at 15° per day
    N c. along the ecliptic at 15° per day
    Y d. along the celestial equator at 15° per hour

2625: Stormy weather is usually associated with regions of __________.

    N a. high barometric pressure
    N b. changing barometric pressure
    Y c. low barometric pressure
    N d. steady barometric pressure

2672: When you are steering on a pair of range lights and find the upper light is in line above the lower light, you should __________.

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

2686: The standard time meridian for description +12 is __________.

    N a. 172.5°E
    Y b. 180.0°
    N c. 172.5°W
    N d. 165.0°W

2766: In low latitudes, the high(s) of the diurnal variation of pressure occur(s) at __________.

    N a. noon
    N b. noon and midnight
    Y c. 1000 and 2200
    N d. 1600

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

3037: The letter H in illustration D006NG represents the __________.

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

3078: Which data must ECDIS be able to record at one-minute intervals?

    N a. Position
    N b. Electronic navigational chart source
    N c. Course made good history
    Y d. All of the above

3085: An ECDIS is required to display which information?

    N a. Water temperature
    N b. Climatology data
    N c. Speed of advance
    Y d. Depth contours