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.


44: The speed of sound through ocean water is nearly always __________.


45: The navigator aboard a ship at approximately 165°E longitude observes the Sun at ZT 14-25-04 on 21 September. What is the GMT and Greenwich date of the observation?


248: What is the index error of sextant A in illustration D050NG? (D050NG )


272: What does the symbol shown indicate on a chart? (D033NG )

    N a. A sunken vessel marked by a buoy
    Y b. A safe water beacon
    N c. A red and white can buoy
    N d. A can buoy with a rotating white light

367: What will be the time after 0800 EST (ZD +5) that the height of the tide at South Freeport, ME, will be 6.0 feet (1.8 meters) on 7 November 1983?

    N a. 0936
    N b. 0942
    Y c. 0951
    N d. 1001

372: You would find the variation on a polyconic projection chart __________.

    Y a. on the compass rose
    N b. on the mileage scale
    N c. written on the chart title
    N d. at each line of longitude

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

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

446: The usual sequence of directions in which a tropical cyclone moves in the Southern Hemisphere is __________.

    N a. northwest, west, and south
    Y b. southwest, south, and southeast
    N c. north, northwest, and east
    N d. west, northwest, and north

471: Yellow lights may appear on __________.

    Y a. special purpose buoys
    N b. vertically-striped buoys
    N c. horizontally-banded buoys
    N d. spherical buoys

532: In a river subject to tidal currents, the best time to dock a ship without the assistance of tugs is __________.

    N a. at high water
    Y b. at slack water
    N c. at flood tide
    N d. when there is a following current

560: On 14 April 1981, a back sight is observed of the lower limb of the Sun. The height of eye is 45 feet. The index error is 2.5' on the arc. The sextant altitude (hs) is 117°14.6'. What is the observed altitude (Ho)?

    N a. 63°01.9'
    N b. 63°03.4'
    N c. 63°07.4'
    Y d. 63°09.9'

562: You wish to measure the distance on a Mercator chart between a point in latitude 42°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 __________.

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

665: 17 degrees of latitude is equal to __________.

    N a. 68 miles
    N b. 510 miles
    Y c. 1020 miles
    N d. 4080 miles

770: You are plotting a running fix in an area where there is a determinable current. How should this current be treated in determining the position?

    Y a. The course and speed made good should be determined and used to advance the LOP.
    N b. The drift should be added to the ship's speed.
    N c. The current should be ignored.
    N d. The set should be applied to the second bearing.

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

841: Under the IALA-A Buoyage system, a buoy marking the port hand of the channel when approaching from seaward may NOT have a __________.

    N a. red light
    Y b. conical shape
    N c. group-flashing light
    N d. square topmark

848: It is unlawful to approach within how many yards of a northern right whale?

    N a. 200
    N b. 300
    N c. 400
    Y d. 500

878: At 0600 ZT on 31 January, your position is LAT 00°49'S, LONG 84°27'E. You are preparing a weather report form, WS Form B-80. How should you encode the first three groups after the call sign if you estimate the wind? (D041NG )

    N a. 30243, 90008, 30848
    N b. 31003, 99049, 38427
    Y c. 31003, 99008, 30844
    N d. 31063, 99049, 58427

936: A cyclone in its final stage of development is called a(n) __________.

    N a. tornado
    N b. anticyclone
    Y c. occluded cyclone or occluded front
    N d. polar cyclone

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

994: Which list of clouds is in sequence, from highest to lowest in the sky?

    N a. Altostratus, cirrostratus, stratus
    Y b. Cirrostratus, altostratus, stratus
    N c. Stratus, cirrostratus, altostratus
    N d. Altostratus, stratus, cirrostratus

1059: The Light List shows that a navigational light has a nominal range of 17 miles and a height above water of 28 feet (8.5 meters). Your height of eye is 32 feet (9.8 meters) and the visibility is 11.0 miles. At what approximate range will you first sight the light?

    N a. 11.0 miles
    Y b. 12.6 miles
    N c. 15.7 miles
    N d. 18.0 miles

1074: As the temperature for a given mass of air increases, the __________.

    N a. dew point increases
    N b. dew point decreases
    N c. relative humidity increases
    Y d. relative humidity decreases

1075: The expression "first magnitude" is usually used to refer only to bodies of magnitude __________.

    Y a. 1.5 and greater
    N b. 1.25 and greater
    N c. 1.0 and greater
    N d. 0.5 and greater

1115: Which light characteristic may be used on a special purpose mark?

    Y a. Flashing
    N b. Occulting
    N c. Equal interval
    N d. Quick flashing

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

1229: The initial great circle course angle between LAT 23°00'S, LONG 42°00'W and LAT 34°00'S, LONG 18°00'E is 063.8°. What is the true course?

    N a. 063.8°T
    Y b. 116.2°T
    N c. 243.8°T
    N d. 296.2°T

1285: You are enroute to assist vessel A. Vessel A is underway at 5.5 knots on course 033°T, and bears 248°T at 64 miles from you. What is the time to intercept if you make 13 knots?

    N a. 4h 55m
    N b. 4h 36m
    N c. 3h 59m
    Y d. 3h 44m

1315: What is a lighted safe water mark fitted with to aid in its identification?

    N a. Red and white retroreflective material
    N b. A sequential number
    Y c. A spherical topmark
    N d. A red and white octagon

1316: When a warm air mass overtakes a cold air mass, the contact surface is called a __________.

    N a. line squall
    N b. water spout
    N c. cold front
    Y d. warm front

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

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

1375: The Moon rises earlier on succeeding days when the __________.

    N a. retardation effect of the revolution of the Moon is greater than the effect due to change of declination
    Y b. effect due to change of declination is larger than that due to revolution
    N c. the revolution effect and the declination effect act in the same direction
    N d. the Moon is on the equator and the revolution effect is at a maximum

1409: You are enroute to assist vessel A. Vessel A is underway at 5.5 knots on course 033°T, and bears 284°T, 43 miles from you. What is the time to intercept if you make 16 knots?

    N a. 2h 16m
    N b. 2h 22m
    Y c. 2h 34m
    N d. 2h 42m

1419: The MOST important feature of the material used for making the binnacle of a standard magnetic compass is that it is __________.

    Y a. nonmagnetic
    N b. weatherproof
    N c. corrosion resistant
    N d. capable of being permanently affixed to the vessel

1432: What benefit is a weather bulletin to a mariner?

    N a. It provides a legal reason to cancel a projected voyage.
    N b. It allows the mariner to make long term weather forecasts.
    N c. It is of little benefit since the weather changes frequently and rapidly.
    Y d. It gives the mariner time to prepare for weather changes.

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

1469: The charted channel depth at Eastport, ME, is 28 feet. You are drawing 31.5 feet and wish 2 feet clearance under the keel. What is the earliest time after 1700 (ZD +4) on 6 September 1983 that you can enter the channel?

    N a. 1825
    N b. 1903
    Y c. 1915
    N d. 2003

1493: You are running parallel to the coast and estimate that the current is against you. In plotting a running fix using bearings from the same object on the coast, the greatest safety margin from inshore dangers will result if what speed is used to determine the fix?

    Y a. Minimum speed estimate
    N b. Maximum speed estimate
    N c. Average speed estimate
    N d. A running fix should not be used under these conditions.

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

1728: If a hurricane several hundred miles away is moving in your general direction your barometer would __________.

    N a. start to rise rapidly
    Y b. start to fall gradually
    N c. rise slowly, begin "pumping" and then start a slow, steady fall
    N d. remain steady

1774: Restricted areas at locks and dams are indicated by __________.

    N a. flashing red lights upstream and fixed red lights downstream
    N b. yellow unlighted buoys
    Y c. signs and/or flashing red lights
    N d. red daymarks upstream and green daymarks downstream

1900: A parallax correction is NOT applied to observations of the __________.

    Y a. stars
    N b. Moon
    N c. Sun
    N d. Planets

2049: At morning stars, the first stars that should be observed are those with an azimuth in which quadrant?

    Y a. Eastern
    N b. Southern
    N c. Western
    N d. Northern

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

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°

2082: You are holding position above Gallipolis Lock and Dam when you hear two long blasts of the horn from the lock. This indicates that you should __________.

    Y a. enter the riverward lock
    N b. hold position until two more upbound tows have locked through
    N c. enter the landward lock
    N d. hold position until the lower gates are closed

2224: By convention, the north seeking ends of a compass' magnets are colored __________.

    N a. black
    N b. blue
    Y c. red
    N d. white

2344: The Moon is subject to four types of libration. Which of the following is NOT one of these types of libration?

    N a. Libration in latitude
    N b. Diurnal libration
    N c. Physical libration
    Y d. Horizontal libration

2370: In the United States, short-range radio navigational warnings are broadcast by the __________.

    Y a. Coast Guard
    N b. Corps of Engineers
    N c. NOAA
    N d. harbor master of the nearest port

2390: You are in a channel in U.S. waters near an industrial plant with a load/discharge facility for barges. You hear a siren being sounded at the facility. What does this indicate?

    Y a. There is danger at the facility due to a fire or cargo release.
    N b. A towboat with a hazardous cargo barge is being moved to or from the facility.
    N c. The facility is warning a barge to shut down transfer operations due to weather conditions (electrical storms, tornado, etc.).
    N d. A barge at the facility has commenced loading or discharging operations.

2396: Perihelion is the point where the Sun __________.

    Y a. is nearest to the Earth
    N b. is farthest from the Earth
    N c. is on the opposite side of the Earth from the Moon
    N d. and Moon and Earth are in line

2446: What is the equivalent of 47 min. 20 sec. in arc units?

    N a. 8°27'
    Y b. 11°50'
    N c. 13°42'
    N d. 13°56'

2530: The distance between any two meridians measured along a parallel of latitude __________.

    N a. increases in north latitude and decreases in south latitude
    N b. decreases as DLO increases
    N c. increases with increased latitude
    Y d. decreases with increased latitude

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)

2821: The height of tide is the __________.

    N a. difference between the depth of the water at high tide and the depth of the water at low tide
    N b. depth of water at a specific time due to tidal effect
    Y c. difference between the depth of the water and the area's tidal datum
    N d. difference between the depth of the water and the high water tidal level

2858: While navigating in fog off a coastline of steep cliffs, you hear the echo of the ships fog horn 2 1/2 seconds after the signal was sounded. What is the distance to the shore?

    N a. 225 yards
    Y b. 460 yards
    N c. 750 yards
    N d. 910 yards

2860: On the Mississippi and Ohio Rivers, there is a special type of fog known as steam fog. It is caused by __________.

    N a. warm air passing over much colder water
    Y b. cold air passing over much warmer water
    N c. a rapid cooling of the ground on a clear night
    N d. rain coming out of a warm air mass aloft

2869: A pillar buoy is indicated by which letter shown in the illustration? (D044NG )

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

2928: You are in a buoyed channel at night and pass a lighted buoy with an irregular characteristic. You should report this to the __________.

    Y a. Coast Guard
    N b. harbor master
    N c. Corps of Engineers
    N d. National Ocean Service

2999: When entering a channel from seaward, the numbers on buoys __________.

    N a. are the same as their Light List number
    N b. are marked in 6 inch figures with retroreflective material
    Y c. increase with the even numbers to starboard
    N d. decrease with the odd numbers to starboard