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.


65: The LMT of LAN is 1210. Your longitude is 70°30'E. Which time would you use to enter the Nautical Almanac to determine the declination of the Sun at LAN?


121: A safe water mark may be __________.


148: When possible, a DR plot should always be started from where?


155: The velocity of the current in large coastal harbors is __________.

    Y a. predicted in Tidal Current Tables
    N b. unpredictable
    N c. generally constant
    N d. generally too weak to be of concern

164: The part of a sextant mounted directly over the pivot of the index arm is the __________.

    Y a. index mirror
    N b. horizon glass
    N c. micrometer drum
    N d. telescope

221: In United States waters, a buoy having red and white vertical stripes has a light characteristic of __________.

    N a. group occulting
    Y b. Morse (A)
    N c. interrupted quick flashing
    N d. quick flashing

224: A sextant having an index error that is "off the arc" has a __________.

    Y a. positive correction
    N b. dip error
    N c. negative correction
    N d. semidiameter error

273: Loran-C is which type of navigation system?

    Y a. Hyperbolic, long-range navigation system
    N b. Short-range electronic
    N c. Long-range, high frequency navigation system
    N d. Long-range, with a frequency of 1950 kHz

320: Sometimes foreign charts are reproduced by NGA (NIMA). On such a chart, a wire-dragged, swept area may be shown in green or __________.

    N a. red
    N b. black
    Y c. purple
    N d. yellow

384: Which is a nonadjustable error of the sextant?

    N a. Error of perpendicularity
    N b. Side error
    N c. Error of collimation
    Y d. Centering error

454: On what does the operation of an aneroid barometer depend?

    Y a. Thin, metal, air tight cell
    N b. Curved tube containing alcohol
    N c. Column of mercury supported by atmospheric pressure
    N d. Expansion of mercury in a closed tube

486: Tropical cyclones do not form within 5° of the Equator because __________.

    N a. there are no fronts in that area
    N b. it is too hot
    N c. it is too humid
    Y d. of negligible Coriolis force

488: A great circle crosses the equator at 93°W. It will also cross the equator at what other longitude?

    N a. 13°E
    Y b. 87°E
    N c. 177°E
    N d. 177°W

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

635: A low HDOP (Horizontal Dilution of Precision) number such as 2 indicates a __________.

    N a. poor fix
    Y b. good fix
    N c. poor signal quality
    N d. good signal quality

702: Which publication contains information on navigation regulations, landmarks, channels, anchorages, tides, currents, and clearances of bridges for Chesapeake Bay?

    Y a. Coast Pilot
    N b. Light List
    N c. Sailing Directions
    N d. Pilot Charts

765: Diurnal aberration is due to __________.

    N a. motion of the Earth in its orbit
    Y b. rotation of the Earth on its axis
    N c. the body's orbital motion during the time required for its light to reach the Earth
    N d. a false horizon

780: Apparent wind speed blowing across your vessel while underway can be measured by a(n) __________.

    N a. barometer
    N b. wind vane
    Y c. anemometer
    N d. thermometer

783: Magnetism which is present only when the material is under the influence of an external field is called __________.

    N a. permanent magnetism
    Y b. induced magnetism
    N c. residual magnetism
    N d. terrestrial magnetism

830: The highest frequency of tropical cyclones in the North Atlantic Ocean occurs during __________.

    N a. January, February and March
    N b. April, May and June
    Y c. August, September and October
    N d. July, November and December

870: Vessels should maintain a sharp lookout, especially during December through March, when navigating the right whale's only known calving grounds which lie off the coasts of __________.

    N a. Nova Scotia
    N b. Maine and Massachusetts
    Y c. Georgia and NE Florida
    N d. California and Mexico

872: Which agency publishes the Light Lists?

    Y a. United States Coast Guard
    N b. National Ocean Service
    N c. Oceanographic Office
    N d. Army Corps of Engineers

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

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

896: The wind direction around a low pressure area in the Northern Hemisphere is __________.

    N a. clockwise and inward
    N b. clockwise and outward
    Y c. counterclockwise and inward
    N d. counterclockwise and outward

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

1019: You are preparing a weather report form, WS Form B-80. The dry bulb thermometer reads 30°F (-1°), and the wet bulb thermometer reads 28°F (-2°C). Using the Ships Code Card, how would you encode the air temperature groups in the report? (D041NG )

    N a. 10011, 2003/
    N b. 11300, 2124/
    N c. 11011, 2124/
    Y d. 11011, 2104/

1023: Which compensates for induced magnetism in the horizontal soft iron of a vessel?

    Y a. Iron spheres mounted on the binnacle
    N b. A single vertical magnet under the compass
    N c. The Flinders bar
    N d. Magnets in trays inside the binnacle

1070: Chart legends which indicate a conspicuous landmark are printed in __________.

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

1162: A line connecting all possible positions of your vessel at any given time is a __________.

    N a. longitude line
    N b. latitude line
    Y c. line of position
    N d. fix

1225: The term "Western Rivers," when it refers to regulations requiring towing vessels to carry navigational-safety equipment, charts or maps, and publications, includes the _____________ .

    N a. Mississippi River and its tributaries
    N b. Port Allen - Morgan City Alternate Route
    N c. Red River and the Old River
    Y d. All of the above

1250: Daylight savings time is a form of zone time that adopts the time __________.

    Y a. one zone to the east
    N b. one zone to the west
    N c. two zones to the east
    N d. two zones to the west

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

1295: The best estimate of the wind direction at sea level can be obtained from observing the direction of the __________.

    N a. cloud movement
    N b. vessel heading
    Y c. waves
    N d. swells

1298: The vertex of a great circle track is in LONG 109°E. An eastbound vessel would cross the equator in LONG __________.

    Y a. 161°W
    N b. 161°E
    N c. 19°E
    N d. 19°W

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

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

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

1581: Shown are the symbols used on radio facsimile weather charts. The symbol indicated at letter "I" represents __________. (D042NG )

    N a. rain showers
    Y b. thunderstorms
    N c. snow storms
    N d. sand storms

1593: Apparent altitude is sextant altitude corrected for __________.

    N a. parallax and personal error
    Y b. inaccuracies in the reading and reference level
    N c. visibility and magnitude
    N d. All of the above are correct

1618: The Light List indicates that a light has a nominal range of 14 miles and is 26 feet high. If the visibility is 4 miles and your height of eye is 20 feet, at what approximate distance will you sight the light?

    Y a. 7.5 miles
    N b. 9.6 miles
    N c. 11.2 miles
    N d. 14.0 miles

1640: Clouds with the prefix "nimbo" in their name __________.

    N a. are sheet or layer clouds
    N b. have undergone great vertical development
    N c. are middle or high altitude clouds
    Y d. are rain clouds

1641: The low, dark, sheet-like cloud which is associated with continuous precipitation for many hours is a __________.

    N a. cirrus cloud
    N b. cumulus cloud
    N c. cumulonimbus cloud
    Y d. nimbostratus cloud

1675: You are entering port and have been instructed to anchor, as your berth is not yet available. You are on a SW'ly heading, preparing to drop anchor, when you observe the range lights as shown on your starboard beam. You should __________. (D047NG )

    N a. NOT drop the anchor until the lights are in line
    Y b. ensure your ship will NOT block the channel or obstruct the range while at anchor
    N c. drop the anchor immediately as the range lights mark an area free of obstructions
    N d. drop the anchor immediately as a change in the position of the range lights will always be an indication of dragging anchor

1677: The position labeled "E" was plotted because __________. (D051NG )

    N a. a dead reckoning position is plotted within a half-hour of each course change
    Y b. a dead reckoning position is plotted for each speed change
    N c. the position is a running fix 1125
    N d. the vessel's position was fixed at 1145

1727: What enables you to estimate the bearing of a storm's center?

    Y a. Buys Ballot's Law
    N b. An educated guess
    N c. Pascal's Law
    N d. The left-hand rule

1771: Which type of precipitation is a product of the violent convection found in thunderstorms?

    N a. Snow
    N b. Freezing Rain
    Y c. Hail
    N d. Sleet

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"

1860: A vessel heading WSW is on a course of __________.

    N a. 202.5°
    N b. 225.0°
    Y c. 247.5°
    N d. 271.0°

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

1987: An instrument useful in predicting fog is the __________.

    Y a. sling psychrometer
    N b. microbarograph
    N c. anemometer
    N d. aneroid barometer

2072: The Illustration represents a movable dam. If a bear trap is open what will be displayed at the lock to indicate this condition? (D037NG )

    Y a. An amber light under a red light
    N b. A white square
    N c. A green triangle
    N d. A yellow pentagon

2111: Vessels regularly navigating Ohio and Mississippi rivers above Cairo, Illinois, and their tributaries, shall at all times have on board a copy of __________.

    N a. Tide Tables
    N b. U.S. Coast Pilot
    Y c. U.S. Army Corps of Engineers Navigation Regulations (Blue Book)
    N d. Sailing Directions

2130: You are underway and pass by a lighthouse. Its light, which was white since you first sighted it, changes to red. This means __________.

    N a. the light is characterized as alternately flashing
    N b. the lighthouse has lost power and has switched to emergency lighting
    N c. it is the identifying light characteristic of the lighthouse
    Y d. you have entered an area of shoal water or other hazard

2258: The primary use of apparent time in marine navigation is to __________.

    N a. calculate sunrise or sunset
    N b. determine zone time
    N c. enter an almanac
    Y d. determine the time of meridian transit

2282: You have completed the magnetic compass adjustments on magnetic east and magnetic south. The vessel is now steady on magnetic west but the compass reads 276°. You should now adjust the compass until it reads __________.

    N a. 264°
    N b. 270°
    Y c. 273°
    N d. Do not adjust the compass, just record the error.

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

2354: 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 blue ends of the magnets are to port you should raise the athwartships tray.
    N b. If the red ends of magnets are to port you should lower the athwartships tray.
    N c. If the red ends of the magnets are aft you should lower the fore-and-aft tray.
    Y d. If the blue ends of the magnets are forward you should raise the fore-and-aft tray.

2392: The point where the Sun is at maximum declination north or south is __________.

    N a. aphelion
    N b. perihelion
    N c. an equinox
    Y d. a solstice

2422: The dimmest stars that could be reasonably used for navigational purposes are of what magnitude?

    N a. First
    Y b. Third
    N c. Sixth
    N d. Tenth

2628: A drawbridge may use visual signals to acknowledge a vessel's request to open the draw. Which signal indicates that the draw will NOT be opened immediately?

    N a. A flashing amber light
    Y b. A fixed red light
    N c. A white flag raised and lowered vertically
    N d. A flashing white light

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