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.


50: The difference between the heights of low and high tide is the __________.


57: The height of tide is the __________.


68: A position obtained by taking lines of position from one object at different times and advancing them to a common time is a(n) __________.


107: The average height of the surface of the sea for all stages of the tide over a 19 year period is called __________.

    N a. mean high water
    N b. mean low water
    N c. half-tide level
    Y d. mean sea level

112: Which chart number indicates an NGA (NIMA) chart designed for inshore coastwise navigation?

    N a. LCORR5868
    N b. COMBT800564
    N c. 17XHA17365
    Y d. 16ACO16595

323: The position accuracy of Loran-C degrades with increasing distance from the transmitting stations as __________.

    N a. gains are made over the signal path
    Y b. a result of variation in propagation conditions
    N c. the frequency of the pulses increases
    N d. the stations shift pulses

338: The illustration shows the symbols used on radio facsimile weather charts. The symbol indicated at letter "N" represents __________. (D042NG )

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

379: The steady current circling the globe at about 60°S is the __________.

    N a. Prevailing Westerly
    N b. Sub-Polar Flow
    Y c. West Wind Drift
    N d. Humboldt Current

502: A gnomonic projection is based on a(n) __________.

    Y a. plane tangent at one point
    N b. cylinder tangent at the equator
    N c. cone tangent at one parallel
    N d. infinite series of cones tangent at selected parallels

549: On a working copy of a weather map, an occluded front is represented by which color line?

    N a. Red
    N b. Blue
    N c. Alternating red and blue
    Y d. Purple

580: On 21 January 1981, you observe a back sight of the Sun's lower limb. The sextant altitude (hs) is 121°31.5'. The index error is 2.5' on the arc. The height of eye is 31 feet (9.3 meters). What is the observed altitude (Ho)?

    N a. 31°06.2'
    Y b. 58°53.1'
    N c. 58°12.2'
    N d. 58°03.2'

649: You are on course 226°T. In order to check the latitude of your vessel, you should observe a celestial body on which bearing?

    N a. 226°
    N b. 270°
    Y c. 000°
    N d. 026°

651: Which topmark shown identifies an isolated danger? (D023NG )

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

671: You sight a buoy fitted with a double-sphere topmark. If sighted at night, this buoy would show a __________.

    N a. quick-flashing red light
    N b. quick-flashing green light
    Y c. flashing white light showing a group of two flashes
    N d. flashing red light showing a group of three flashes

685: Thirty-two meters equals __________.

    N a. 17.50 feet
    N b. 58.52 feet
    N c. 96.00 feet
    Y d. 104.99 feet

742: You are preparing to take a tow from San Diego to Portland, OR. Good seamanship would require that you have on board, available for reference and use, all of the following EXCEPT the __________.

    N a. Coast Pilot
    N b. harbor and coastal charts for ports of refuge enroute
    Y c. Sailing Directions (Enroute)
    N d. Light List

754: Deviation in a compass is caused by the __________.

    N a. vessel's geographic position
    N b. vessel's heading
    N c. earth's magnetic field
    Y d. influence of the magnetic materials of the vessel

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

832: What is the most important source of information to be used in correcting charts and keeping them up to date?

    N a. Fleet Guides
    Y b. Notice to Mariners
    N c. Sailing Directions
    N d. Pilot Charts

917: As the South Equatorial Current approaches the east coast of Africa, it divides with the main part flowing south to form the warm __________.

    Y a. Agulhas Current
    N b. Canary Current
    N c. Benguela Current
    N d. Madagascar Current

921: Under the IALA-B Buoyage System, a conical buoy will be __________.

    Y a. red in color
    N b. numbered with an odd number
    N c. left to port when entering from seaward
    N d. All of the above

939: That half of the hurricane to the right hand side of its track (as you face the same direction that the storm is moving) in the Northern Hemisphere is called the __________.

    N a. windward side
    N b. leeward side
    N c. safe semicircle
    Y d. dangerous semicircle

1049: At 0000 you fix your position and change course to 270°T. At 0030 you again fix your position, and it is 0.5 mile east of your DR. Which statement is TRUE?

    N a. The set is 090°, drift 0.5 knot.
    Y b. The set is 090°, drift 1.0 knot.
    N c. The set is 270°, drift 0.5 knot.
    N d. The set is 270°, drift 1.0 knot.

1063: When adjusting a magnetic compass using the fore-and-aft permanent magnets, you should __________.

    N a. use the magnets one at a time, putting one in one side and then one on the opposite side, one step higher.
    N b. use the magnets in pairs, starting at the top, with trays at the highest point of travel
    Y c. use the magnets in pairs, from the bottom up, with the trays at the lowest point of travel
    N d. fill all the trays with magnets, then remove them one-by-one until the deviation is removed

1131: On navigational aids, what does the light characteristic "Fl(2+1)" mean?

    N a. A flashing light combined with a fixed light of greater brightness
    Y b. Light flashes combined in groups, with a different number of flashes in each group
    N c. A light showing groups of two or more flashes at regular intervals
    N d. A fixed light varied at regular intervals by groups of two or more flashes of greater brightness

1173: When adjusting a magnetic compass for error, a deviation table should be made __________.

    N a. before correcting for any deviation
    N b. after correcting for variation
    Y c. after adjusting the fore-and-aft and athwartships permanent magnets
    N d. before the quadrantal correctors are placed on the compass

1272: What are the colors of a mid-channel daymark?

    N a. Black and red
    Y b. Red and white
    N c. Green and red
    N d. Green and white

1306: What type of clouds are associated with a cold front?

    N a. Altostratus and fracto-cumulus
    N b. Altostratus and cirrus
    N c. Cirrus and cirrostratus
    Y d. Cumulus and cumulonimbus

1324: When daylight savings time is kept, the time of tide and current calculations must be adjusted. One way of doing this is to __________.

    Y a. add one hour to the times listed under the reference stations
    N b. subtract one hour from the time differences listed for the subordinate stations
    N c. apply no correction as the times in the reference stations are adjusted for daylight savings time
    N d. add 15° to the standard meridian when calculating the time difference

1342: An occluded front on a weather map is colored __________.

    N a. blue line
    Y b. purple line
    N c. dashed blue line
    N d. alternate red and blue line

1425: Which is an inferior planet?

    N a. Mars
    Y b. Venus
    N c. Neptune
    N d. Pluto

1465: The planet Venus can be observed in the morning before sunrise if it is well to the __________.

    Y a. west of and higher than the Sun
    N b. west of and lower than the Sun
    N c. east of and higher than the Sun
    N d. east of and lower than the Sun

1476: When warm moist air blows over a colder surface and is cooled below its dew point, the result is __________.

    N a. radiation fog
    N b. ice fog
    Y c. advection fog
    N d. frost smoke

1570: The navigational triangle uses parts of two systems of coordinates, one of which is the horizon system and the other is the __________.

    N a. terrestrial system
    N b. astronautical system
    Y c. celestial equator system
    N d. ecliptic system

1596: You are sailing south on the Intracoastal Waterway (ICW) when you sight a red nun buoy with a yellow square painted on it. Which of the following is TRUE?

    Y a. You should leave the buoy on your port hand.
    N b. This buoy marks the end of the ICW in that geographic area.
    N c. The yellow is retroreflective material used to assist in sighting the buoy at night.
    N d. The yellow square is in error and it should be a yellow triangle.

1661: Advection fog may be formed by warm moist air passing over a __________.

    N a. warmer sea surface
    Y b. cooler sea surface
    N c. dry coastal plain
    N d. polar land mass

1710: A gale is characterized by a wind speed of __________.

    N a. 10 to 20 knots
    Y b. 34 to 47 knots
    N c. 48 to 63 knots
    N d. 64 to 83 knots

1741: The left half of the storm is called the navigable semicircle because __________.

    N a. the wind speed is decreased by the storm's forward motion
    N b. the wind tends to blow vessels away from the storms track
    Y c. Both A and B
    N d. Neither A nor B

1811: To find a magnetic compass course from a true course you must apply __________.

    N a. deviation
    Y b. deviation and variation
    N c. variation
    N d. magnetic anomalies (local disturbances)

1848: The buoy symbol printed on your chart is leaning to the northeast. This indicates __________.

    N a. you should stay to the north or east of the buoy
    N b. you should stay to the west or south of the buoy
    N c. the buoy is a major lighted buoy
    Y d. nothing special for navigational purposes

1969: The precession of the equinoxes of the Earth is __________.

    N a. the gradual increase in the period of rotation caused by the effects of the Moon
    N b. the irregularity of the Earth's orbit caused by influences of the Sun and Moon
    N c. caused by the elliptical shape of the Earth's orbit
    Y d. similar to a top spinning with its axis tilted

1979: The principal vertical circle is that great circle on the celestial sphere that passes through the __________.

    N a. zenith and the celestial body
    Y b. zenith and the north and south poles
    N c. poles and Greenwich
    N d. zenith and is parallel to the horizon

2097: 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 __________.

    N a. Sailing Directions
    Y b. Broadcast Notice to Mariners
    N c. Light List Vol. V
    N d. None of the above

2110: You are underway in a vessel with a draft of 6.0 feet. You are in an area where the charted depth of the water is 4 fathoms. You would expect the depth of water beneath your keel to be approximately __________.

    N a. 12 feet
    Y b. 18 feet
    N c. 24 feet
    N d. 30 feet

2146: What lights would you see on the Illinois water way when any wickets of the dam or bear traps are open, or partially open, which may cause a set in the current conditions in the upper lock approach?

    N a. Green over red
    N b. Red over blue
    Y c. Red over amber (yellow)
    N d. None of the above

2177: This 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. One amber light
    N b. Three red lights
    N c. Two red lights
    Y d. One red light

2268: What condition exists at perigee?

    N a. The Earth is farthest from the Sun.
    N b. The Earth, Sun, and Moon are in line.
    N c. The Earth, Sun, and Moon are at right angles.
    Y d. The Moon is closest to the Earth.

2320: The type of current which will have the greatest effect on the course made good for your vessel is __________.

    N a. one flowing in the same direction as your course steered
    N b. one flowing in the opposite direction as your course steered
    Y c. one that flows at nearly right angles to your course steered
    N d. a rotary current in which the direction of current flow constantly changes

2436: Aphelion is the point where the Sun __________.

    N a. and Moon and Earth form a right angle
    N b. and Moon and Earth are in line
    N c. crosses the celestial equator
    Y d. is farthest from the Earth

2546: A structure, usually made of stone, or cement pilings, which extends from the bank at approximately right angles to the current is called a __________.

    Y a. dike
    N b. revetment
    N c. cutoff
    N d. crib

2594: At McAlpine L & D, normal upper pool elevation is 420.0 feet (130.8 meters) MSL, equal to 12.0 feet (3.7 meters) on the upper gage. The vertical clearance at the Clark Memorial Highway bridge is 72.6 feet (22.1 meters) above normal pool. What is the clearance if the gage reads 10.6 feet (3.2 meters)?

    N a. 84.6 feet (25.8 meters)
    N b. 83.2 feet (25.4 meters)
    Y c. 74.0 feet (22.6 meters)
    N d. 62.0 feet (18.9 meters)

2636: You are ascending a river and exchanging navigational information via radiotelephone with a descending vessel. If the descending vessel advises you to "watch for the set" above point X, what would you expect to encounter above point X?

    N a. An increase in current velocity
    N b. Slack water
    N c. Shallow water
    Y d. A sideways movement of your vessel

2678: A vessel crossing a river on the Western Rivers, must keep out of the way of a power-driven vessel __________.

    N a. descending the river with a tow
    N b. ascending the river with a tow
    N c. ascending the river without a tow
    Y d. All of the above

2682: Sidereal time is used by navigators when __________.

    N a. used with the equation of time
    Y b. used in the form of LHA Aries
    N c. calculating the time of moonrise
    N d. determining local apparent time

2716: Under the U.S. Aids to Navigation System on the Western Rivers, passing daymarks on the left descending bank are __________.

    N a. green squares
    N b. green diamonds
    N c. red diamonds
    Y d. red triangles

2794: The standard atmospheric pressure in millibars is __________.

    N a. 760.0
    N b. 938.9
    N c. 1000.0
    Y d. 1013.2

3007: A rotary current sets through all directions of the compass. The time it takes to complete one of these cycles, in a locale off the East coast of the US, is approximately __________.

    N a. 2 1/2 hours
    N b. 3 1/2 hours
    N c. 6 1/4 hours
    Y d. 12 1/2 hours

3008: You take a bearing of 086° of a lighthouse. Which bearing of another object would give the best fix?

    N a. 291°
    N b. 261°
    N c. 242°
    Y d. 196°

3068: Which of the following data layer categories is NOT displayed on ECDIS?

    N a. Notice to Mariners information
    N b. ECDIS warnings and messages
    Y c. Ship hydrodynamic information
    N d. Hydrographic Office data

3130: When may the automatic identification system (AIS) be switched off?

    N a. At anytime as long as it is properly logged.
    Y b. At the Master's professional judgment.
    N c. Only when the vessel is at anchor or in port.
    N d. Under no circumstance.