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.


48: When should a navigator rely on the position of floating aids to navigation?


94: When using a recording depth finder in the open ocean, what phenomena is most likely to produce a continuous trace that may not be from the actual ocean bottom?


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


124: An electronic depth finder operates on the principle that __________.

    N a. radio signals reflect from a solid surface
    Y b. sound waves travel at a constant speed through water
    N c. radar signals travel at a constant speed through water
    N d. pressure increases with depth

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 __________.

    N a. the equator to the elevated pole
    Y b. your horizon to your zenith
    N c. your zenith to the elevated pole
    N d. the geographical position of the Sun to the elevated pole

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

154: Which factor has the greatest effect on the amount of gain required to obtain a fathometer reading?

    N a. Salinity of water
    N b. Temperature of water
    N c. Atmospheric pressure
    Y d. Type of bottom

163: How many fixed objects are needed to plot a running fix?

    N a. None
    Y b. One
    N c. Two
    N d. Three

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

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

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

405: At upper transit, if the zenith distance is 34°, the geographical distance from the observer to a body's GP is __________.

    N a. 510 miles
    N b. 1220 miles
    Y c. 2040 miles
    N d. 2260 miles

429: A great circle crosses the equator at 127°W. It will also cross the equator at what other longitude?

    N a. 127°E
    Y b. 53°E
    N c. 27°E
    N d. 27°W

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

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'

579: Low pressure disturbances, which travel along the intertropical convergence zone, are called __________.

    N a. permanent waves
    N b. tidal waves
    Y c. tropical waves
    N d. tropical storms

603: What is the approximate wave length of an X Band Radar operating on a frequency of approximately 9500 MHz?

    Y a. 3 cm
    N b. 10 cm
    N c. 30 cm
    N d. 100 cm

678: On 25 December 1981 you observe the Sun's lower limb. The sextant altitude (hs) is 4°06.9'. The height of eye is 47 feet and the index error is 1.6' on the arc. The temperature is 19°F. and the barometer reads 1030.8 millibars. What is the observed altitude (Ho)?

    N a. 3°57.4'
    Y b. 4°01.9'
    N c. 4°02.5'
    N d. 4°03.4'

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

775: A sidereal day is shorter than a solar day. This difference is due to __________.

    N a. irregularities in the daily rotational rate of the Sun
    N b. the space motion of the solar system
    N c. the precession of the equinoxes
    Y d. the use of different reference points

784: Variation is the angular measurement between __________.

    N a. compass north and magnetic north
    N b. compass north and true north
    Y c. magnetic meridian and the geographic meridian
    N d. your vessel's heading and the magnetic meridian

959: What is the index error of sextant B in illustration D050NG? (D050NG )

    N a. 0'30" off the arc
    N b. 1'00" off the arc
    Y c. 3'30" off the arc
    N d. 1'30" on the arc

1025: A first magnitude star is __________.

    Y a. 2.5 times as bright as a second magnitude star
    N b. 3 times as bright as a second magnitude star
    N c. 5 times as bright as a second magnitude star
    N d. 10 times as bright as a second magnitude star

1089: 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 course to steer at 13 knots to intercept vessel A?

    Y a. 262°
    N b. 269°
    N c. 276°
    N d. 281°

1129: The motion of celestial bodies relative to other celestial bodies is known as __________.

    Y a. space motion
    N b. apparent motion
    N c. diurnal motion
    N d. actual motion

1179: Which type of cloud is indicated by the number 3? (DO39NG )

    Y a. Cirrocumulus
    N b. Altocumulus
    N c. Nimbostratus
    N d. Cumulus

1207: What will be the velocity of the tidal current at New London Harbor Entrance, CT, at 1615 EST (ZD +5) on 26 December 1983?

    Y a. 0.2 knot
    N b. 0.4 knot
    N c. 0.7 knot
    N d. 0.9 knot

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

1287: What will be the velocity of the tidal current 4.5 miles east of Smith Point, VA, at 0630 DST (ZD +4) on 6 May 1983?

    Y a. 0.3 knot
    N b. 0.5 knot
    N c. 0.7 knot
    N d. 1.0 knot

1377: What is the velocity of the tidal current at the east end of Pollock Rip Channel at 1700 DST (ZD +4) on 23 July 1983?

    N a. 0.6 knot ebbing
    N b. 0.8 knot flooding
    Y c. 1.5 knots flooding
    N d. 1.9 knots flooding

1380: Which type of weather could you expect soon after seeing "hook" or "comma" shaped cirrus clouds?

    Y a. Rain with the approach of a warm front
    N b. Clearing with the approach of a cold front
    N c. Continuing fog and rain
    N d. The formation of a tropical depression

1438: In the Northern Hemisphere you are caught in the dangerous semicircle of a storm with plenty of sea room available. The best course of action is to bring the wind on the __________.

    N a. port quarter and make as much headway as possible
    N b. starboard quarter and make as much headway as possible
    Y c. starboard bow and make as much headway as possible
    N d. port bow and make as much headway as possible

1478: Altostratus clouds are indicated by which number? (D039NG )

    N a. 1
    Y b. 4
    N c. 7
    N d. 8

1479: A microbarograph is a precision instrument that provides a __________.

    N a. charted record of atmospheric temperature over time
    Y b. charted record of atmospheric pressure over time
    N c. graphic record of combustible gases measured in an atmosphere
    N d. graphic record of vapor pressure from a flammable/combustible liquid

1504: The time meridian used when computing the height of tide for Pensacola Bay, FL, is __________.

    N a. 75°00'W
    N b. 82°30'W
    Y c. 90°00'W
    N d. 97°30'W

1508: A line of position is __________.

    N a. a line connecting two charted objects
    Y b. a line on some point of which the vessel may be presumed to be located
    N c. the position of your vessel
    N d. not used in a running fix

1576: You are entering an east coast port and see a buoy with a yellow triangle painted on it. This indicates __________.

    Y a. you are in the vicinity of the ICW
    N b. the buoy is a special mark
    N c. the buoy is off station
    N d. the buoy designates a sharp turn in the channel

1579: You get underway from the oil terminal at Marcus Hook, PA, at 0815 ZT (ZD +5) on 20 February 1983, enroute to sea. You will be turning for 11 knots. What is the approximate current when you are abreast Reedy Island?

    N a. Slack
    Y b. 2.0 knots ebbing
    N c. 1.5 knots flooding
    N d. 0.5 knot flooding

1584: A decrease in barometric pressure is associated with all of the following except __________.

    N a. rising warm air
    N b. proximity to a low pressure area
    N c. inward spiraling circulation
    Y d. clear dry weather

1603: 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
    Y b. fix
    N c. running fix
    N d. dead-reckoning position

1606: Aids to navigation marking the intracoastal waterway can be identified by __________.

    N a. the letters ICW after the aid's number or letter
    Y b. yellow stripes, squares, or triangles marked on them
    N c. white retroreflective material
    N d. the light characteristic and color for lighted aids

1658: Fog forms when the air temperature is at or below __________.

    N a. 32° F
    N b. the wet bulb temperature
    Y c. the dew point
    N d. the dry bulb temperature

1715: The hurricane season generally occurs from __________.

    N a. August to January
    N b. July to December
    Y c. June to November
    N d. January to June

1718: A hurricane is characterized by winds of __________.

    N a. up to 33 knots
    N b. 34 to 47 knots
    N c. 48 to 63 knots
    Y d. 64 knots or greater

1765: Which meteorological feature controls the climate of the Gulf and the Gulf Coast area during late spring and summer?

    Y a. The Bermuda High
    N b. The doldrums
    N c. The horse latitudes
    N d. Tropical cyclones

1785: Which factor(s) is/are used to develop the charted information of a lighthouse?

    N a. Height of the light and the observer
    Y b. Height and brightness of the light
    N c. Brightness of the light and height of the observer
    N d. Height of the light only

2314: 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 blue ends of the magnets are forward you should raise the fore-and-aft tray.
    N b. If the blue ends of the magnets are aft you should lower the fore-and-aft tray.
    Y c. If the blue ends of the magnets are aft, and the fore-and-aft tray is at the top, you should add some magnets.
    N d. If the blue ends of the magnets are aft, and the fore-and-aft tray is at the bottom, you should reverse the magnets.

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'

2508: Normal pool elevation is the height in feet of the section of river above a dam. This height is measured from __________.

    N a. low steel on the Huey P. Long Bridge
    Y b. mean sea level
    N c. the local water table
    N d. the minimum dam control level

2610: A line on the Earth parallel to the equator is a __________.

    N a. gnomonic curve
    Y b. small circle
    N c. meridian
    N d. great circle

2624: You must construct a Mercator plotting sheet on a piece of paper measuring 30" by 32". The area includes latitudes 31°10'S to 37°40'S and longitudes 007°00'W to 001°00'E. Allow a one-half inch neat line on all sides. What is the maximum distance between each degree of longitude that will permit the area of the plotting sheet to be drawn within the stated limitation?

    Y a. 3.69 inches
    N b. 3.52 inches
    N c. 3.38 inches
    N d. 3.26 inches

2664: The Light List shows a lighted aid to navigation on the right bank. This means that the light can be seen on the port side of a vessel __________.

    N a. crossing the river
    N b. descending the river
    Y c. ascending the river
    N d. proceeding towards sea

2689: The letter D in illustration D006NG represents __________. (D006NG )

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

2809: The diurnal variation of pressure is not visible in the middle latitudes in winter because __________.

    Y a. it is masked by the pressure changes of moving weather systems
    N b. the decreased gravitational effect from the sun causes the variation to fade
    N c. the decreased average temperature is less than the critical temperature
    N d. the increased Coriolis force disperses the pressure variation

2836: The correction tables in the front of the Nautical Almanac for use with sun sights do NOT include the effects of __________.

    N a. mean refraction
    N b. parallax
    N c. semidiameter
    Y d. irradiation

2899: You take a bearing of 043° and 169° of two objects. What bearing of a third object will give the best fix?

    N a. 356°
    N b. 073°
    N c. 192°
    Y d. 309°

2908: A daymark used to indicate the port side of the channel when approaching from seaward is indicated by what letter in illustration D045NG?

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

2940: On the Corps of Engineer's Navigation Maps, the channel is __________.

    N a. midway between the banks
    N b. indicated by depths (in feet)
    Y c. indicated by a broken line
    N d. not indicated

2986: Some places maintain a zone time of -13. What are the time and date at Greenwich if the zone time and date are 2152, 10 January?

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

3101: The typical operating range of automatic identification systems (AIS) at sea is nominally __________.

    N a. 2 nm
    N b. 8 nm
    Y c. 20 nm
    N d. 40 nm