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.


15: What is the length of a nautical mile?


70: The station located at "A" is the __________. (D001NG )


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


171: Under the U.S. Aids to Navigation System, a lighted buoy with a spherical topmark marks __________.

    Y a. safe water
    N b. a fish trap area
    N c. a hazard to navigation
    N d. a bifurcation in the channel

231: You are outbound in a buoyed channel on course 015°T. You sight a white light showing a Morse (A) characteristic bearing 359° relative. For safety, you should __________.

    N a. change course to 359°T to pass near to the buoy
    Y b. stay in the channel and leave the buoy to port
    N c. alter course to 000°T and leave the buoy well clear to starboard
    N d. check the chart to see where the marked danger lies in relation to the buoy

236: The winds with the greatest effect on the set, drift, and depth of the equatorial currents are the __________.

    N a. doldrums
    N b. horse latitudes
    Y c. trade winds
    N d. prevailing westerlies

244: To make sure of getting the full advantage of a favorable current, you should reach an entrance or strait at what time in relation to the predicted time of the favorable current?

    N a. One hour after the predicted time
    N b. At the predicted time
    N c. 30 minutes before flood, one hour after an ebb
    Y d. 30 minutes before the predicted time

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

335: What is the geographic longitude of a body whose GHA is 232°27'?

    Y a. 127°33'E
    N b. 52°27'E
    N c. 61°52'W
    N d. 61°52'E

455: The height of eye correction is smaller than geometrical dip because of __________.

    N a. the angle between the horizontal and the line of sight to the visible horizon
    N b. index error
    N c. parallax
    Y d. terrestrial refraction

487: What will be the time after 0600 (ZD +3), on 6 March 1983, that the height of the tide at Puerto Rosales, Argentina, will be 9.0 feet (2.7 meters)?

    N a. 0740
    N b. 0754
    N c. 0840
    Y d. 0922

548: When the declination of the Moon is 0°12.5'S, you can expect some tidal currents in Gulf Coast ports to __________.

    N a. have either a double ebb or a double flood
    N b. become reversing currents
    Y c. become weak and variable
    N d. exceed the predicted velocities

572: You wish to measure the distance on a Mercator chart between a point in latitude 43°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 __________.

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

606: Early indications of the approach of a hurricane may be all of the following EXCEPT __________.

    Y a. short confused swells
    N b. gradually increasing white clouds (mare's tails)
    N c. pumping barometer
    N d. continuous fine mist-like rain

608: In which voyage, between two points, is the rhumb line distance NOT approximately the same as the great circle distance?

    N a. The two points are in low latitudes in the same hemisphere.
    Y b. The two points are in high latitudes in the same hemisphere.
    N c. The two points are near the equator, but in different hemispheres.
    N d. One point is near the equator, one point is in a high latitude, and both are near the 180th meridian.

630: What kind of weather would you expect to accompany the passage of a tropical wave?

    Y a. Heavy rain and cloudiness
    N b. Good weather
    N c. A tropical storm
    N d. Dense fog

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

667: The navigable semicircle of a typhoon in the Southern Hemisphere is the area __________.

    N a. behind the typhoon, measured from 90° to 180°From each side of the storm's track
    Y b. to the right of the storm's track
    N c. ahead of the typhoon, measured from the storm's track to 90° on each side
    N d. measured from due south, counterclockwise 180°

718: You are to sail from Elizabethport, NJ, on 22 May 1983 with a maximum draft of 28 feet. You will pass over an obstruction in the channel near Sandy Hook that has a charted depth of 27 feet. The steaming time from Elizabethport to the obstruction is 1h 40m. What is the earliest time (ZD +4) you can sail on the afternoon of 22 May and pass over the obstruction with 3 feet of clearance?

    Y a. 1407
    N b. 1331
    N c. 1303
    N d. 1242

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

729: The doldrums are characterized by __________.

    N a. steady, light to moderate winds
    Y b. frequent calms
    N c. clear skies
    N d. low humidity

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

810: The position labeled B is a(n) __________. (D051NG )

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

871: Under the IALA-A Buoyage System, a buoy marking the starboard side of the channel when approaching from seaward must have a(n) __________.

    N a. pillar shape
    Y b. green color
    N c. square topmark
    N d. even number

922: How is the intensity of a light expressed in the Light Lists?

    N a. Luminous range
    N b. Geographic range
    Y c. Nominal range
    N d. Meteorological range

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

956: Good weather is usually associated with a region of __________.

    N a. low barometric pressure
    Y b. high barometric pressure
    N c. falling barometric pressure
    N d. pumping barometric pressure

1027: In the Northern Hemisphere the major ocean currents tend to flow __________.

    Y a. clockwise around the North Atlantic and North Pacific Oceans
    N b. clockwise or counterclockwise depending on whether it is warm or cold current
    N c. counterclockwise except in the Gulf Stream
    N d. counterclockwise around the North Atlantic and North Pacific Oceans

1180: You are on course 238°T. To check the course of your vessel you should observe a celestial body on which bearing?

    N a. 180°
    N b. 238°
    Y c. 328°
    N d. 090°

1203: If the compass heading and the magnetic heading are the same then __________.

    N a. the deviation has been offset by the variation
    N b. there is something wrong with the compass
    N c. the compass is being influenced by nearby metals
    Y d. there is no deviation on that heading

1214: The letter B in the diagram represents the __________. (D006NG )

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

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

1275: How is variation indicated on a small-scale nautical chart?

    N a. Magnetic compass table
    N b. Magnetic meridians
    Y c. Isogonic lines
    N d. Variation is not indicated on small-scale nautical charts.

1276: Which weather change accompanies the passage of a cold front in the Northern Hemisphere?

    N a. Wind shift from northeast, clockwise to southwest
    N b. Steady dropping of barometric pressure
    N c. Steady precipitation, gradually increasing in intensity
    Y d. A line of cumulonimbus clouds

1491: You are on course 138°T. To check the latitude of your vessel you should observe a celestial body on which bearing?

    N a. 138°
    N b. 270°
    N c. 318°
    Y d. 000°

1506: You are steaming southward along the west coast of the United States when you sight a buoy showing a flashing green light. How should you pass this buoy?

    N a. Leave it to your port.
    Y b. Leave it to your starboard.
    N c. Pass it close aboard on either side.
    N d. Pass it on either side but well clear of it.

1550: Cirrus clouds are indicated by which number? (D039NG )

    Y a. 1
    N b. 4
    N c. 5
    N d. 7

1577: Yesterday your chronometer read 11h 59m 59s at 1200 GMT time tick. Today the chronometer reads 12h 00m 01s at the 1200 GMT tick. What is the chronometer rate?

    N a. -1s
    N b. +1s
    N c. -2s
    Y d. +2s

1882: The GP of a body for a high altitude sight is determined from the Greenwich hour angle and the __________.

    N a. circle of equal altitude
    N b. zenith distance
    N c. azimuth angle
    Y d. declination

1922: In the North Sea area, you sight a buoy showing a quick white light with 9 flashes every 15 seconds. Which of the four topmarks shown would be fitted to the buoy? (D030NG )

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

1972: The point on the celestial sphere that is directly over the observer is the __________.

    N a. node
    N b. pole
    Y c. zenith
    N d. nadir

2000: A vessel heading SE is on a course of __________.

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

2044: What is the relative bearing of an object broad on the port quarter?

    N a. 195°
    Y b. 225°
    N c. 240°
    N d. 265°

2054: The diagram is of a fixed C of E lock and dam. What navigational light(s) is(are) exhibited at the position indicated by the letter B? (D038NG )

    N a. One red light
    N b. Two green lights
    N c. Three green lights
    Y d. No lights

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

2216: A vessel is heading magnetic northwest and its magnetic compass indicates a heading of 317°. What action should be taken to remove this error during compass adjustment?

    N a. Move the quadrantal spheres out.
    Y b. Move the quadrantal spheres in.
    N c. If the spheres are in as far as possible replace them with smaller spheres.
    N d. If the spheres are out as far as possible replace them with smaller spheres.

2274: A vessel is heading magnetic east and its magnetic compass indicates a heading of 086°. What action should be taken to remove this error during compass adjustment?

    N a. If the red ends of the magnets are to port you should lower the athwartships tray.
    N b. If the blue ends of the magnets are to port, and the athwartships tray is at the top, you should reverse the magnets.
    N c. If the red ends of the magnet are aft, and the fore-and-aft tray is at the top, you should add some more magnets.
    Y d. If the red ends of the magnets are aft you should lower the fore-and-aft tray.

2298: The period of rotation of the Moon on its axis is __________.

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

2364: The immediate surroundings of what constellation contain the most first magnitude stars?

    N a. Libra
    N b. Cassiopeia
    N c. Pegasus
    Y d. Orion

2402: You have completed the magnetic compass adjustments on magnetic east and magnetic south. The vessel is now steady on magnetic north but the compass reads 356°. You should now adjust the compass until it reads __________.

    Y a. 358°
    N b. 000°
    N c. 002°
    N d. 004°

2408: What is the equivalent of 42 min. 48 sec. in arc units?

    N a. 21°24'
    N b. 18°16'
    N c. 11°19'
    Y d. 10°42'

2442: You have completed the magnetic compass adjustments on magnetic east and magnetic south. The vessel is now steady on magnetic north but the compass reads 004°. You should now adjust the compass until it reads __________.

    N a. 356°
    N b. 358°
    N c. 000°
    Y d. 002°

2505: At the approaches to Savannah, GA, with the wind coming out of the west, the wind-driven current will be flowing approximately __________.

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

2740: When one upbound vessel is overtaking another vessel and both are pushing a tow ahead, what reaction may you expect?

    N a. Both towheads will tend to drift apart, and the overtaking vessel will be slowed down.
    N b. Both towheads will tend to drift together, and the overtaking vessel will be slowed down.
    Y c. Both towheads will tend to drift apart, and the overtaken vessel will be slowed down.
    N d. Both towheads will tend to drift together, and the overtaken vessel will be slowed down.

2866: Some locations maintain a zone time of -13. What are the zone time and date if the Greenwich time and date are 2152, 10 January?

    N a. 1052, 9 January
    N b. 0852, 10 January
    N c. 1052, 10 January
    Y d. 1052, 11 January

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

2961: Which position includes the effects of wind and current?

    N a. Dead reckoning positions
    Y b. Estimated positions
    N c. Leeway position
    N d. Set position

2962: While navigating in fog off a coastline of steep cliffs, you hear the echo of the ship's fog horn 4 1/2 seconds after the signal was sounded. What is the distance to the shore?

    N a. 405 yards
    N b. 628 yards
    N c. 730 yards
    Y d. 825 yards

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

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