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.


47: The range of tide is the __________.


116: Which wind results from a land mass cooling more quickly at night than an adjacent water area?


150: An alternating light __________.


154: Which factor has the greatest effect on the amount of gain required to obtain a fathometer reading?

    N a. Salinity of water
    N b. Temperature of water
    N c. Atmospheric pressure
    Y d. Type of bottom

165: On 6 July 1981, at 1000 zone time, you cross the 180th meridian steaming westward. What is your local time?

    N a. It is 1000, 5 July.
    N b. It is 1000, 6 July.
    N c. It is 2200, 7 July.
    Y d. It is 1000, 7 July.

287: The datum from which the predicted heights of tides are reckoned in the tide tables is the same as that used for the charts of the locality. The depression of the datum below mean sea level for Hampton Roads, Virginia is __________.

    N a. between -.7 and +.5 feet
    N b. between 1.9 and 3.2 feet
    N c. 4.1 feet
    Y d. 1.2 feet

296: The wind flow from the horse latitudes to the doldrums is deflected due to __________.

    Y a. Coriolis force
    N b. the mid-latitude, semi-permanent high
    N c. differing atmospheric pressures
    N d. the prevailing westerlies

302: Which symbol represents a 20-fathom curve?

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

304: In order to remove index error from a sextant, you should adjust the __________.

    N a. index mirror to make it parallel to the horizon glass with the index set at zero
    Y b. horizon glass to make it parallel to the index mirror with the index set at zero
    N c. horizon glass to make it parallel to the sextant frame
    N d. telescope to make it perpendicular to the sextant frame

376: According to Buys Ballot's law, when an observer in the Northern Hemisphere experiences a northeast wind the center of low pressure is located to the __________.

    N a. northeast
    N b. west-southwest
    N c. northwest
    Y d. south-southeast

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

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

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

540: A white buoy with an orange rectangle on it is used to indicate __________.

    N a. danger
    N b. a controlled area
    N c. an exclusion area
    Y d. general information

587: Your vessel has a draft of 34 feet. On 8 October 1983 you wish to pass over an obstruction near Jaffrey Point, NH, that has a charted depth of 31 feet. Allowing for a safety margin of 3 feet, what is the earliest time after 0900 DST (ZD +4) that this passage can be made?

    N a. 0920
    Y b. 1029
    N c. 1120
    N d. 1159

650: What classification of tropical cyclone would have closed isobars, counter clockwise rotary circulation, and sustained winds between 34 and 63 knots?

    N a. A tropical disturbance
    N b. A tropical depression
    Y c. A tropical storm
    N d. A hurricane

721: Under the IALA Buoyage System, a red and white vertically-striped buoy would NOT indicate __________.

    N a. a landfall
    Y b. the extreme end of an islet
    N c. a mid-channel
    N d. a center line

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

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

748: You are steaming west in the South Atlantic in an extratropical cyclonic storm, and the wind is dead ahead. According to the law of Buys Ballot, the center of low pressure lies __________.

    N a. to the north of you
    Y b. to the south of you
    N c. dead ahead of you
    N d. dead astern of you

796: Cyclones tend to move __________.

    N a. perpendicular to the isobars in their warm sectors
    Y b. parallel to the isobars in their warm sectors
    N c. parallel to the line of the cold front
    N d. perpendicular to the line of the cold front

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

    N a. the Philippines
    Y b. Australia
    N c. Republic of Korea
    N d. Chile

949: In Region A of the IALA Buoyage System, when entering from seaward, the port side of a channel would be marked by a __________.

    N a. black can buoy
    Y b. red can buoy
    N c. black conical buoy
    N d. red conical buoy

976: The atmosphere in the vicinity of a high pressure area is called a(n) __________.

    Y a. anticyclone
    N b. cold front
    N c. occluded front
    N d. cyclone

1026: An air mass that has moved down from Canada would most likely have the symbols __________.

    N a. mPk
    Y b. cPk
    N c. cTk
    N d. cTw

1126: When a warm air mass is adjacent to a cold air mass, the separation line between the two is called a(n) __________.

    Y a. front
    N b. isobar
    N c. isotherm
    N d. equipotential line

1145: The GHA of a star __________.

    Y a. increases at a rate of approximately 15° per hour
    N b. increases at a rate of approximately 4° per hour
    N c. decreases at a rate of approximately 15° per hour
    N d. decreases at a rate of approximately 4° per hour

1434: What is NOT a characteristic of cardinal marks?

    N a. Yellow and black bands
    N b. White lights
    Y c. Square or triangular topmarks
    N d. Directional orientation to a hazard

1443: At the master gyrocompass, the compass card is attached to the __________.

    N a. spider element
    Y b. sensitive element
    N c. link arm
    N d. pickup transformer

1485: The safest and most prudent procedure to follow while navigating in the vicinity of a tropical cyclone is to __________.

    Y a. take positive steps to avoid it if possible
    N b. batten down and prepare to ride out the storm
    N c. continue to navigate farther from the coast
    N d. always navigate towards the coast by the most direct route

1492: You are planning a voyage from San Francisco to Japan. Which publication contains information on the ocean routes?

    N a. Coast Pilot
    Y b. Sailing Directions (Planning Guide)
    N c. Sailing Directions (Enroute)
    N d. World Port Index

1507: When you are steering on a pair of range lights and find the upper light is above the lower light you should __________.

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

1526: A single barometric pressure reading of 28.60 indicates __________.

    N a. rapidly improving weather
    N b. deteriorating weather
    Y c. a severe low pressure system
    N d. fair weather and calm

1578: The LMT of sunrise on the standard meridian is 0552. Your longitude is 99°15'E. What is your ZT of sunrise?

    N a. 0512
    N b. 0529
    N c. 0552
    Y d. 0615

1581: Shown are the symbols used on radio facsimile weather charts. The symbol indicated at letter "I" represents __________. (D042NG )

    N a. rain showers
    Y b. thunderstorms
    N c. snow storms
    N d. sand storms

1607: When your barometer reading changes from 30.25 to 30.05 in a 12-hour period it indicates __________.

    N a. rapidly changing weather
    N b. improving weather
    N c. high winds within the next six hours
    Y d. little or no immediate change

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

1675: You are entering port and have been instructed to anchor, as your berth is not yet available. You are on a SW'ly heading, preparing to drop anchor, when you observe the range lights as shown on your starboard beam. You should __________. (D047NG )

    N a. NOT drop the anchor until the lights are in line
    Y b. ensure your ship will NOT block the channel or obstruct the range while at anchor
    N c. drop the anchor immediately as the range lights mark an area free of obstructions
    N d. drop the anchor immediately as a change in the position of the range lights will always be an indication of dragging anchor

1722: Hurricanes may move in any direction. However, it is rare and generally of short duration when a hurricane in the Northern Hemisphere moves toward the __________.

    N a. west or northwest
    N b. northeast
    Y c. southeast
    N d. north

1725: Your present weather is sunny with a steady barometer. A low swell approaches your vessel from the south with crests passing at relatively long periods of about four per minute. This usually indicates __________.

    N a. a warm front from the south
    Y b. a tropical cyclone south of your vessel
    N c. a hurricane about 100 miles south of your vessel and heading in your direction
    N d. an extra-tropical cyclone

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

1775: The letter A in illustration D006NG represents the __________.

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

1778: Illustration D037NG represents a movable dam. If the wickets are down and there are open weirs due to high water, what light(s) will be shown at A if the lock walls and piers are not awash? (D037NG )

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

1840: A vessel heading NW is on a course of __________.

    N a. 274.5°
    N b. 292.5°
    Y c. 315.0°
    N d. 337.5°

1885: Under the Uniform State Waterway Marking System a mooring buoy is painted __________.

    Y a. white with a blue band
    N b. yellow
    N c. any color that does not conflict with the lateral system
    N d. white with a green top

1890: A vessel heading SSE is on a course of __________.

    N a. 112.5°
    N b. 135.0°
    Y c. 157.5°
    N d. 180.0°

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

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

1942: In the horizon system of coordinates what is equivalent to the declination of the equator system?

    N a. Nadir
    N b. Azimuth angle
    Y c. Altitude
    N d. Zenith distance

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

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

2007: Information about the direction and velocity of rotary tidal currents is found in the __________.

    N a. Mariner's Guide
    Y b. Tidal Current Tables
    N c. Nautical Almanac
    N d. Tide Tables

2022: The GP of a body for a high altitude sight is determined from the declination and the __________.

    N a. right ascension
    N b. sidereal hour angle
    Y c. Greenwich hour angle
    N d. observed altitude

2052: Under the chart numbering system used by NGA (NIMA), the first digit of a multi-digit number indicates __________.

    Y a. the general geographic area
    N b. the general scale of the chart
    N c. whether it is a major or minor chart
    N d. the projection used to construct the chart

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°

2121: In plotting a running fix, how many fixed objects are needed to take your lines of position from?

    N a. Three
    N b. Two
    Y c. One
    N d. None

2170: The temperature at which the air is saturated with water vapor and below which condensation of water vapor will occur is referred to as the __________.

    N a. precipitation point
    N b. vapor point
    Y c. dew point
    N d. absolute humidity

2189: 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. If the blue ends are to port and the athwartships tray is at the bottom, you should add some more magnets.
    N b. If the blue ends are to port and the athwartships tray is at the top, you should add some more magnets.
    N c. If the red ends are to port, you should lower the athwartships tray.
    Y d. If the red ends are to port and the tray is at the bottom, you should raise the tray.

2516: Apparent time is based on __________.

    N a. a fictitious sun moving along the celestial equator
    Y b. the visible sun moving along the ecliptic
    N c. the Moon's motion in relation to the Sun
    N d. the movement of the first point of Aries

2910: 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°
    N b. 45°
    Y c. 90°
    N d. 30°

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

3121: The short text messaging feature of the automatic identification system (AIS) allows for messages of up to___.

    N a. 64 characters
    N b. 96 characters
    Y c. 158 characters
    N d. 256 characters