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.


104: What should you apply to a fathometer reading to determine the depth of water?


118: What describes an accurate position that is NOT based on any prior position?


129: In working out a local apparent noon sight for your latitude, you subtract the Ho from 90°. The 90° represents the angular distance from __________.


264: Which of the four adjustable errors in the sextant is the principle cause of index error?

    N a. Telescope not being parallel to the frame
    Y b. Index mirror and horizon glass not being parallel
    N c. Index mirror not being perpendicular to the frame
    N d. Horizon glass not being perpendicular to the frame

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

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

369: You are underway on course 050°T and your maximum speed is 11 knots. The eye of a hurricane bears 070°T, 80 miles from your position. The hurricane is moving towards 270°T at 19 knots. What course should you steer at 11 knots to have the maximum CPA?

    N a. 250°
    N b. 234°
    N c. 227°
    Y d. 215 °

491: A special purpose buoy shall be __________.

    N a. lighted with a white light
    N b. striped black and red
    N c. lighted with a red light
    Y d. yellow

515: The small circle of the celestial sphere parallel to the celestial equator, and transcribed by the daily motion of the body, is called the __________.

    N a. hour circle of the body
    Y b. parallel of declination
    N c. vertical circle of the body
    N d. parallel of altitude

598: A great circle crosses the equator at 141°E. It will also cross the equator at what other longitude?

    N a. 180°E
    N b. 41°E
    N c. 141°W
    Y d. 39°W

661: Under the IALA Buoyage Systems, safe water marks may show a __________.

    N a. composite group-flashing, Fl(2 + 1), red light
    N b. composite group-flashing, Fl(2 + 1), green light
    N c. quick-flashing, Q(9)15s, white light
    Y d. white Morse (A) light

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

776: You are navigating in pilotage waters using running fixes. The maximum time between fixes should be about __________.

    N a. 4 hours
    N b. 1 hour
    Y c. 30 minutes
    N d. 5 minutes

816: Cyclones that have warm sectors usually move __________.

    N a. westerly
    Y b. parallel to the isobars in the warm sector
    N c. toward the nearest high pressure area
    N d. faster than the accompanying cold front

825: While steering a course of 150°T, you wish to observe the Sun for a speed check. What would the azimuth have to be?

    N a. 000°T
    N b. 090°T
    Y c. 150°T
    N d. 240°T

888: Recurvature of a hurricane's track usually results in the forward speed __________.

    Y a. increasing
    N b. decreasing
    N c. remaining the same
    N d. varying during the day

938: If within 500 yards (460m) of a Northern Right Whale you are lawfully obligated to __________.

    N a. turn away from the whale and leave at full speed
    Y b. turn away from the whale and leave at slow speed
    N c. slow to bare steerageway until the whale swims away
    N d. stop the vessel and sound repeated blasts on the ship's whistle to scare the whale away

952: What is TRUE concerning new editions of Light Lists?

    N a. Supplements to new editions are issued monthly by the U.S. Coast Guard.
    N b. New editions are published by the National Ocean Service.
    Y c. New editions are corrected through the date shown on the title page.
    N d. None of the above

962: Chart legends which indicate a conspicuous landmark are printed in __________.

    N a. underlined letters
    N b. boldfaced print
    N c. italics
    Y d. capital letters

991: You are underway in the North Sea on course 328°T when you sight a buoy broad on your port bow. You are in the best navigable water if the buoy __________.

    N a. has a topmark of two cones with points down
    N b. is a western quadrant buoy
    N c. is painted yellow on the top half and black on the bottom
    Y d. exhibits a light with the characteristic of VQ(3)5s

1090: What weather conditions would you expect to find at position A? (D049NG )

    Y a. Winds NW-W at 15 knots, partly cloudy, and slight seas
    N b. winds SW-S at 20 knots, heavy rain, and rough seas
    N c. Winds calm, light rain, and calm seas
    N d. Winds NE-E at 20 knots, heavy rain, and rough seas

1092: The wind velocity is higher in the dangerous semicircle of a tropical cyclone because of the __________.

    N a. extension of the low pressure ridge
    Y b. wind circulation and forward motion of the storm
    N c. recurvature effect
    N d. direction of circulation and pressure gradient

1110: 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. At the predicted time
    Y b. 30 minutes before the predicted time
    N c. One hour after the predicted time
    N d. 30 minutes before flood, one hour after an ebb

1171: A light that has a light period shorter than its dark period is described as __________.

    Y a. flashing
    N b. pulsating
    N c. occulting
    N d. alternating

1246: What 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

1279: For 3 November 1983, at 0830 EST (ZD +5) at Catskill, NY, what is the predicted height of tide?

    N a. +0.1 foot (+0.0 m)
    Y b. -0.6 foot (-0.2 m)
    N c. +0.9 foot (+0.3 m)
    N d. -1.3 feet (-0.4 m)

1341: The height of a light is measured from which reference plane?

    N a. Mean low water
    Y b. Mean high water
    N c. Average water level
    N d. Geographical sea level

1352: Weather observations provided by each weather station include all of the following except __________.

    N a. temperature
    N b. visibility
    Y c. predicted weather for the next twelve hours
    N d. barometric pressure and change in the last three hours

1370: Which type of cloud is indicated by the number 8? (D039NG )

    N a. Cumulonimbus
    N b. Altostratus
    N c. Cirrostratus
    Y d. Nimbostratus

1382: The chart indicates the variation was 3°45'W in 1988, and the annual change is increasing 6'. If you use the chart in 1991 how much variation should you apply?

    N a. 3°27'W
    N b. 3°27'E
    Y c. 4°03'W
    N d. 4°03'E

1517: When determining compass error by an azimuth of Polaris, you enter the Nautical Almanac with the __________.

    N a. GHA Aries
    Y b. LHA Aries
    N c. LHA Polaris
    N d. GHA Polaris

1521: To avoid error you should read the scale of an aneroid barometer with your eye placed __________.

    N a. to the right of the pointer
    N b. to the left of the pointer
    Y c. directly in front of the pointer
    N d. slightly above the meniscus

1545: The change in the length of day becomes greater as latitude increases because of the __________.

    N a. inclination of the diurnal circle to the equator
    N b. decreasing distance between the terrestrial meridians
    Y c. increased obliquity of the celestial sphere
    N d. changing distance between the earth and the sun

1604: The Illustration shows the symbols used on radio facsimile weather charts. Which of these symbols indicates freezing rain? (D042NG )

    N a. M
    N b. N
    N c. O
    Y d. P

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)

1659: The type of fog that occurs on clear nights with very light breezes and forms when the earth cools rapidly by radiation is known as __________.

    Y a. radiation fog
    N b. frontal fog
    N c. convection fog
    N d. advection fog

1723: The intensity of a hurricane as it reaches higher latitudes and cooler waters __________.

    N a. Increases
    N b. remains the same
    Y c. decreases
    N d. None of the above

1766: You are approaching a lock and see a flashing amber light located on the lock wall. You should __________.

    N a. stand clear of the lock entrance
    Y b. approach the lock under full control
    N c. enter the lock as quickly as possible
    N d. hang off your tow on the lock wall

1783: You can follow the approach of a dangerous cyclonic storm by inspecting __________.

    N a. the National Weather Service Observing Handbook No.1, Marine Surface Observations
    Y b. a weather fax
    N c. the Coast Pilot or Sailing Directions
    N d. the sky overhead

1805: A phenomenon where the atmospheric pressure is higher than that of other surrounding regions is called __________.

    N a. the "trade winds"
    N b. a low front or an occluded front
    N c. the doldrums
    Y d. a "high"

1986: The Moon is farthest from the Earth at __________.

    N a. the full Moon
    Y b. apogee
    N c. the lunar solstice
    N d. quadrature

2066: 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. One red light
    N b. Two red lights
    Y c. Three red lights
    N d. No lights

2101: Information about major breakdowns, repairs, or other emergency operations with regard to weirs and (or) wicket dams, on the western rivers, may be obtained by consulting the __________.

    Y a. Broadcast Notice to Mariners
    N b. Light List Vol. V
    N c. U.S. Coast Pilot
    N d. All of the above

2127: 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
    N b. One red light
    N c. Two red lights
    Y d. Three red lights

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.

2252: The vertical angle between the horizontal and the magnetic line of force is the __________.

    N a. elevation
    N b. magnetic angle
    N c. vertical angle
    Y d. dip

2312: Mars is only seen at two phases, one of which __________.

    Y a. is the full phase
    N b. is conjunction
    N c. occurs only at sunset or sunrise
    N d. occurs at or near 0° elongation

2345: You should plot your dead reckoning position __________.

    N a. from every estimated position
    N b. every three minutes in pilotage waters
    N c. only in pilotage waters
    Y d. from every fix or running fix

2350: The principal advantage of NAVTEX radio warnings is that __________.

    Y a. they can be used by mariners who do not know Morse code
    N b. only an ordinary FM radio is necessary to receive these warnings
    N c. information on a given topic is only broadcast at specified times
    N d. they cover a broad spectrum of the radio band allowing reception on almost any type of receiver

2374: The largest of the navigational planets is __________.

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

2394: A vessel is heading magnetic east and its magnetic compass indicates a heading of 093°. What action should be taken to remove this error during compass adjustment?

    N a. If the red ends of the magnets are aft, and the fore-and-aft tray is at the top, you should remove some magnets.
    N b. If the red ends of the magnet are aft, and the fore-and-aft tray is at the bottom, you should reverse the magnets.
    Y c. If the red ends of the magnets are aft you should raise the fore-and-aft tray.
    N d. If the blue ends of the magnets are forward you should remove some magnets from the fore-and-aft tray.

2409: You are approaching the first of two drawbridges that span a narrow channel. The second drawbridge is close to the first. Which signals should you sound?

    N a. Sound the request-for-opening signal for the first bridge only, who will notify the second bridge of your approach
    N b. Sound the request-for-opening signal twice in succession to indicate you must pass through both bridges
    N c. Sound the request-for-opening signal, pause for about 10 seconds, then sound two prolonged blasts.
    Y d. Sound the request-for-opening signal and, after the bridge acknowledges it, sound the request-for-opening signal for the second bridge.

2432: A time diagram is a diagram of the celestial sphere as observed from above the __________.

    Y a. south celestial pole
    N b. north celestial pole
    N c. observer's meridian
    N d. Greenwich meridian

2456: An orange and white buoy marking an area where operating restrictions are in effect will be marked with which symbol?

    N a. Open-faced diamond
    N b. Diamond with a cross
    Y c. Circle
    N d. Rectangle

2459: The controlling depth of the river is __________.

    N a. the minimum depth of the river prescribed in the channel maintenance program
    N b. the edge of a dredged channel
    N c. the highest level to which the river may rise without flooding
    Y d. the least available water in a channel which limits the draft of boats and tows

2567: When outbound from a U.S. port, a buoy displaying a flashing red light indicates __________.

    N a. a sharp turn in the channel to the right
    N b. a wreck to be left on the vessel's starboard side
    N c. a junction with the preferred channel to the left
    Y d. the port side of the channel

2578: You must draw a plotting sheet covering latitudes 49°N to 53°N and longitudes 179°E to 178°W. If the distance between latitude 49°N to 53°N is 16 inches, what is the distance between the meridians of 1° of longitude?

    N a. 2.12 inches
    N b. 2.33 inches
    Y c. 2.56 inches
    N d. 2.81 inches

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

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.

2810: When steering a tow downstream around the shape of a sand bar, and staying on the proper side of the buoys, an operator should be cautious of __________.

    Y a. eddies under the bar
    N b. swift current under the bar causing loss of control
    N c. cross-currents pushing the tow away from the bar
    N d. cross-currents pushing the tow into the bar

3031: Which symbol would indicate a large automated navigational buoy, such as those that have replaced some lightships? (D015NG )

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