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.


23: If Loran-C signals become unsynchronized, the receiver operator is warned because __________.


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 __________.


98: A position that is obtained by applying estimated current and wind to your vessel's course and speed is a(n) __________.


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

    N a. 12h 30m
    N b. 12h 44m
    Y c. 12h 58m
    N d. 13h 22m

151: Under the U.S. Aids to Navigation System, spherical buoys may be __________.

    N a. numbered
    Y b. lettered
    N c. lighted
    N d. All of the above

168: Your vessel is making way through the water at a speed of 12 knots. Your vessel traveled 30 nautical miles in 2 hours 20 minutes. What current are you experiencing?

    N a. A following current at 2.0 knots
    N b. A head current of 2.0 knots
    Y c. A following current of 0.9 knot
    N d. A head current of 0.9 knot

260: The National Ocean Service publishes the __________.

    N a. Light Lists
    Y b. Coast Pilots
    N c. pilot charts
    N d. Sailing Directions

285: The apparent wind is zero when the true wind is __________.

    N a. zero
    N b. from ahead and equal to the ship's speed
    Y c. from astern and equal to the ship's speed
    N d. from astern and is twice the ship's speed

430: The southeast trade winds actually blow toward the __________.

    N a. southeast
    N b. south
    N c. east
    Y d. northwest

434: The purpose of the "set" hand on an aneroid barometer is to __________.

    N a. adjust the barometer
    Y b. indicate any change in the reading of the barometer
    N c. provide a correction for height above sea level
    N d. provide a correction for temperature changes

456: Which condition exists in the eye of a hurricane?

    N a. Wind rapidly changing direction
    N b. A temperature much lower than that outside the eye
    N c. Towering cumulonimbus clouds
    Y d. An extremely low barometric pressure

467: At what time after 1400 EST (ZD +5), on 4 January 1983, will the height of the tide at Port Wentworth, GA, be 3.0 feet?

    N a. 1612
    N b. 1630
    Y c. 1653
    N d. 1718

593: Radar makes the most accurate determination of the __________.

    N a. direction of a target
    Y b. distance to a target
    N c. size of a target
    N d. shape of a target

676: If you are caught in the left semicircle of a tropical storm, in the Southern Hemisphere, you should bring the wind __________.

    N a. on the starboard quarter, hold course and make as much way as possible
    N b. 2 points on the port quarter, and make as much way as possible
    Y c. on the port bow, and make as much way as possible
    N d. dead ahead and heave to

865: The radius of a circle of equal altitude of a body is equal to the __________.

    Y a. coaltitude of the body
    N b. altitude of the body
    N c. codeclination of the body
    N d. polar distance

901: Under the IALA-A Buoyage System, a buoy indicating that the preferred channel is to port when entering from seaward, can have a __________.

    N a. can shape
    N b. group-flashing (2) light
    N c. red-and-green vertical stripes
    Y d. green light

940: What is the length of a nautical mile?

    Y a. 6,076 feet
    N b. 5,280 feet
    N c. 2,000 yards
    N d. 1,850 meters

986: A warm air mass is characterized by __________.

    Y a. stability
    N b. instability
    N c. gusty winds
    N d. good visibility

993: When crossing the magnetic equator the __________.

    N a. Flinders bar should be inverted
    Y b. heeling magnet should be inverted
    N c. the quadrantal spheres should be rotated 180°
    N d. Flinders bar should be moved to the opposite side of the binnacle

1041: You are steaming along the coast of Ireland in the Irish Sea. You sight a lighted buoy with a white flashing light showing a group of two flashes. The buoy indicates you __________.

    N a. must pass south of the buoy
    N b. must pass north of the buoy
    Y c. should pass well clear on either side of the buoy
    N d. must pass the buoy close to starboard

1044: The dry-bulb temperature is 78°F and the wet-bulb temperature is 62°F. What is the relative humidity?

    N a. 16%
    N b. 24%
    Y c. 39%
    N d. 79%

1045: The Light List shows that a navigational light has a nominal range of 15 miles and a height above water of 40 feet (12.2 meters). Your height of eye is 25 feet (7.6 meters) and the visibility is 5 miles. At about what range will you FIRST sight the light?

    N a. 6.2 miles
    Y b. 9.5 miles
    N c. 12.9 miles
    N d. 14.2 miles

1078: The description "Racon" beside an illustration on a chart would mean a __________.

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

1108: Preferred channel buoys indicate the preferred channel to transit by __________.

    N a. odd or even numbers
    Y b. the color of their top band
    N c. the location of the buoy in the channel junction
    N d. the buoy's light rhythms

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

1166: A series of brief showers accompanied by strong, shifting winds may occur along or some distance ahead of a(n) __________.

    N a. upper front aloft
    N b. cyclone
    N c. occluded front
    Y d. cold front

1188: The magnitude of three stars is indicated. Which star is the brightest?

    N a. Antares + 1.2
    N b. Altair + 0.9
    Y c. Vega + 0.1
    N d. Cannot be determined; magnitude indicates size not brightness

1274: The Illustration shows the symbols used on radio facsimile weather charts. Which of these symbols indicates a sandstorm? (D042NG )

    N a. H
    Y b. O
    N c. P
    N d. K

1334: The Illustration shows the symbols used on radio facsimile weather charts. The symbol indicated at letter "H" represents __________. (D042NG )

    N a. ice
    N b. snow
    N c. rain
    Y d. hail

1378: The latitude of the upper vertex of a great circle is 36°N. What is the latitude of the lower vertex?

    N a. 36°N
    N b. 0°
    Y c. 36°S
    N d. Cannot be determined from the information given

1437: Determine the time after 0300 CST (ZD +6) when the velocity of the tidal current will be 0.5 knot on 16 April 1983, at Port Arthur Canal Entrance, TX.

    N a. 0436
    Y b. 0507
    N c. 0538
    N d. 0554

1510: During daylight savings time the meridian used for determining the time is located farther __________.

    N a. west
    Y b. east
    N c. east in west longitude and west in east longitude
    N d. west in west longitude and east in east longitude

1539: You are steaming in the open ocean of the North Pacific between the Aleutian Chain and Hawaii. A warning broadcast indicates that an earthquake has occurred in the Aleutians and has generated a tsunami that is predicted to hit Hawaii. What action is necessary for the ship's safety?

    N a. Calculate the tsunami's ETA at your position and turn to a course that will head into the Tsunami.
    N b. Securely stow all loose gear, check deck lashings, and prepare for extreme rolls.
    Y c. No special action as tsunamis are inconspicuous in the open ocean
    N d. Prepare for sudden, high-velocity wind gusts from rapidly changing directions.

1543: The distance between the surface of the water and the tidal datum is the __________.

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

1572: Generally speaking, in the Northern Hemisphere, when winds are blowing from between SE and SW the barometric reading __________.

    N a. makes no change at all
    Y b. is somewhat lower than it would be for winds from a northern quadrant
    N c. is uncertain and may fluctuate by increasing and decreasing
    N d. is somewhat higher than it would be for winds from the northern quadrant

1624: A psychrometer has two thermometers that provide dry bulb and wet bulb temperatures. By comparing these two temperature readings with a set of tables you can determine the __________.

    N a. atmospheric pressure
    N b. wind speed
    Y c. relative humidity and dew point
    N d. wind chill factor

1704: If the center of low pressure is due west of you in the Northern Hemisphere, which wind direction should you expect?

    N a. South to west
    Y b. South to east
    N c. West to north
    N d. North to east

1709: The Beaufort scale is used to estimate the __________.

    N a. wind direction
    N b. percentage of cloud cover
    Y c. wind speed
    N d. barometric pressure

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

1816: A white buoy with an orange circle marked on it indicates __________.

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

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

2140: The visible range marked on charts for lights is the __________.

    N a. minimum distance at which the light may be seen with infinite visibility
    N b. minimum distance at which the light may be seen based on a 12 mile distance to visible horizon
    N c. maximum distance the light may be seen restricted by the height of the light and the curvature of the earth
    Y d. maximum distance at which a light may be seen in clear weather with 10 miles visibility

2140: The visible range marked on charts for lights is the __________.

    N a. minimum distance at which the light may be seen with infinite visibility
    N b. minimum distance at which the light may be seen based on a 12 mile distance to visible horizon
    N c. maximum distance the light may be seen restricted by the height of the light and the curvature of the earth
    Y d. maximum distance at which a light may be seen in clear weather with 10 miles visibility

2187: The diagram 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. No lights
    N b. Three red lights
    N c. Two red lights
    Y d. One red lights

2188: 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?

    Y a. If the red ends are to starboard the athwartships magnets should be lowered.
    N b. If the blue ends are forward the fore-and-aft magnets should be raised.
    N c. If the red ends are to starboard and the tray is at the top add some athwartships magnets.
    N d. If the blue ends are aft the fore-and-aft magnets should be raised.

2202: You have completed the magnetic compass adjustments on magnetic east and magnetic south. The vessel is now steady on magnetic west but the compass reads 276°. What action should be taken?

    N a. Adjust the compass with the athwartships magnets until the compass reads 264°.
    Y b. Adjust the compass with the fore-and-aft magnets until the compass reads 273°.
    N c. Adjust the compass with the quadrantal spheres until the compass reads 270°.
    N d. Adjust the compass with the athwartships magnets until the compass reads 273°.

2282: You have completed the magnetic compass adjustments on magnetic east and magnetic south. The vessel is now steady on magnetic west but the compass reads 276°. You should now adjust the compass until it reads __________.

    N a. 264°
    N b. 270°
    Y c. 273°
    N d. Do not adjust the compass, just record the error.

2346: The first point of Aries is the point where the Sun is at __________.

    N a. maximum declination north
    N b. maximum declination south
    Y c. 0° declination going to northerly declinations
    N d. 0° declination going to southerly declinations

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

2504: Under the IALA-A Buoyage System, when entering from seaward a lateral system buoy to be left to starboard may display which topmark shown? (D046NG )

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

2679: Under the U.S. Aids to Navigation System on the Western Rivers, a daymark on the right descending bank will __________.

    Y a. be green
    N b. have an odd number
    N c. indicate the gage reading
    N d. have yellow retroreflective markings

2725: A position that is obtained by using two or more intersecting lines of position taken at nearly the same time, is a(n) __________.

    N a. estimated position
    N b. dead-reckoning position
    N c. running fix
    Y d. fix

2741: A general chart could have a scale of __________.

    Y a. 1:200,000
    N b. 1:1,000,000
    N c. 1:50,000
    N d. not more than 1:25,000

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

2822: While navigating in fog off a coastline of steep cliffs, you hear the echo of the ships fog horn 2 seconds after the signal was sounded. What is the distance to the shore?

    Y a. 360 yards
    N b. 320 yards
    N c. 280 yards
    N d. 140 yards

2844: The signal from a ramark will show on the PPI as a __________.

    N a. coded signal on the same bearing and at a greater range then the transponder
    N b. circle surrounding the transponder
    Y c. radial line from the transponder to the center of the PPI
    N d. dashed circle at the same range as the transponder

2887: The letter B in illustration D006NG represents the __________.

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

2947: A position obtained by crossing lines of position taken at different times and advanced to a common time is a(n) __________.

    N a. fix
    N b. dead-reckoning position
    Y c. running fix
    N d. estimated position

2980: What volume of the Coast Guard Light List is used for the Mississippi River system?

    N a. I
    N b. II
    N c. IV
    Y d. V

3129: Which of the following statements is TRUE regarding automatic identification systems (AIS) ?

    Y a. The master may, at his/her discretion, turn off the AIS if he/she believes that it may compromise the safety or security of the vessel.
    N b. Under no circumstances shall AIS be turned off while underway as this could endanger the vessel and those around her.
    N c. AIS is always required to be operating if the vessel is in or in the vicinity of a VTS area.
    N d. AIS is always required to be operating if the vessel is within 100 nautical miles of the coastline.