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.


5: A vessel is steaming in east longitude on January 25 and crosses the International Date Line on an eastbound course at 0900 zone time. What is the date and time at Greenwich when the vessel crosses the line?


46: What wind reverses directions seasonally?


56: A strong, often violent, northerly wind occurring on the Pacific coast of Mexico, particularly during the colder months, is called __________.


70: The station located at "A" is the __________. (D001NG )

    N a. on station
    N b. off station
    Y c. master station
    N d. secondary station

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

    N a. Subtract the draft of the vessel.
    Y b. Add the draft of the vessel.
    N c. Subtract the sea water correction .
    N d. Add the sea water correction.

133: The line connecting the Loran-C master station with a secondary station is called the __________.

    N a. focus line
    Y b. base line
    N c. side line
    N d. center line

137: Priming of the tides occurs __________.

    N a. at times of new and full Moon
    N b. when the Earth, Moon, and Sun are lying approximately on the same line
    N c. when the Moon is between first quarter and full and between third quarter and new
    Y d. when the Moon is between new and first quarter and between full and third quarter

213: When using GPS, how many theoretical position lines are required for a two-dimensional fix?

    N a. 1
    N b. 2
    Y c. 3
    N d. 4

243: The loran lines drawn on navigation charts represent __________.

    Y a. ground waves
    N b. skywaves
    N c. either ground waves or skywaves interchangeably
    N d. an average between ground wave and skywave positions

294: What is a nonadjustable error of the sextant?

    Y a. Prismatic error
    N b. Index error
    N c. Side error
    N d. Error of collimation

426: The wind speed and direction observed from a moving vessel is known as __________.

    N a. coordinate wind
    N b. true wind
    Y c. apparent wind
    N d. anemometer wind

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

663: You are underway at 10 knots. At 1800 you note a radar contact dead ahead at a range of 10 miles. At 1812 the contact is dead ahead at a range of 8 miles. The estimated speed of the contact is __________.

    Y a. dead in the water
    N b. 5 knots
    N c. 10 knots
    N d. 15 knots

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

718: You are to sail from Elizabethport, NJ, on 22 May 1983 with a maximum draft of 28 feet. You will pass over an obstruction in the channel near Sandy Hook that has a charted depth of 27 feet. The steaming time from Elizabethport to the obstruction is 1h 40m. What is the earliest time (ZD +4) you can sail on the afternoon of 22 May and pass over the obstruction with 3 feet of clearance?

    Y a. 1407
    N b. 1331
    N c. 1303
    N d. 1242

734: You are approaching Chatham Strait from the south in foggy weather. You have Coronation Island and Hazy Islands on the radar. Suddenly the radar malfunctions. You then resort to using whistle echoes to determine your distance off Coronation Island. Your stopwatch reads 16.3 seconds for the echo to be heard. How far are you off Coronation Island?

    N a. 1.0 mile
    Y b. 1.5 miles
    N c. 2.0 miles
    N d. 2.5 miles

761: Under the IALA Buoyage Systems, a safe water mark may NOT __________.

    N a. be spherical
    N b. display a white light
    N c. be lettered
    Y d. show a quick flashing light

845: During one synodic rotation, a body makes one complete turn relative to the __________.

    N a. Earth
    Y b. Sun
    N c. stars
    N d. vernal equinox

868: Your ship received a HYDROLANT advising of a special warning to mariners from the Department of State for ships in the Persian Gulf. You are 400 miles south of, and bound for, the Persian Gulf. What action should you take?

    N a. Continue on course as the warning is advisory in nature only.
    Y b. Send an AMVER report and acknowledge receipt of the warning.
    N c. Remain a minimum of 500 miles outside the Persian Gulf and maintain radio silence.
    N d. Send a MERWARN message advising your position, course, speed and intentions.

887: Which current would you encounter on a direct passage from southern Africa to Argentina, South America?

    Y a. South Atlantic
    N b. South Equatorial
    N c. Agulhas
    N d. Guinea

898: At 1200 ZT, on 31 July, your position is LAT 24°33'N, LONG 173°05'W. 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 )

    Y a. 01003, 99245, 71731
    N b. 01243, 92433, 71731
    N c. 31243, 99245, 71731
    N d. 31003, 92433, 71730

933: How many degrees are there on a compass card?

    Y a. 360°
    N b. 380°
    N c. 390°
    N d. 420°

934: Clouds that form as small white flakes or scaly globular masses covering either small or large portions of the sky are __________.

    N a. cirrus
    N b. cirrostratus
    N c. altostratus
    Y d. cirrocumulus

954: A thin, whitish, high cloud popularly known as "mares' tails" is __________.

    N a. altostratus
    N b. stratus
    N c. cumulus
    Y d. cirrus

1004: A low, uniform layer of cloud resembling fog, but not resting on the ground, is called __________.

    N a. cumulus
    N b. nimbus
    Y c. stratus
    N d. cirrus

1013: The purpose of the soft iron spheres mounted on arms on the binnacle is to compensate for __________.

    N a. the vertical component of the permanent magnetism of the vessel
    N b. the residual deviation
    N c. magnetic fields caused by electrical currents in the vicinity
    Y d. induced magnetism in the horizontal soft iron

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/

1022: What is the approximate geographic range of Fenwick Island Light, Delaware, if your height of eye is 37 feet (11.6 meters)? Refer to "Reprints from the LIGHT LISTS AND COAST PILOTS" .

    N a. 24.8 nm
    Y b. 17.8 nm
    N c. 15.9 nm
    N d. 10.3 nm

1127: In a river subject to tidal currents, the best time to dock a ship without the assistance of tugs is __________.

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

1127: In a river subject to tidal currents, the best time to dock a ship without the assistance of tugs is __________.

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

1132: On charts of U.S. waters, a magenta marking is NOT used for marking a __________.

    N a. radio beacon
    Y b. 5-fathom curve
    N c. prohibited area
    N d. lighted buoy

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

1247: What is the predicted velocity of the tidal current 2 miles west of Southwest Ledge for 2330 DST (ZD +4) on 7 September 1983?

    Y a. 1.3 knots
    N b. 1.6 knots
    N c. 1.9 knots
    N d. 2.2 knots

1251: A List of Lights entry (L Fl) is a single flashing light which shows a long flash of not less than __________.

    N a. 1.0 second duration
    N b. 1.5 seconds duration
    Y c. 2.0 seconds duration
    N d. 3.0 seconds duration

1470: The Illustration shows the symbols used on radio facsimile weather charts. Which symbol indicates a hurricane? (D042NG )

    N a. M
    N b. I
    N c. L
    Y d. K

1485: The safest and most prudent procedure to follow while navigating in the vicinity of a tropical cyclone is to __________.

    Y a. take positive steps to avoid it if possible
    N b. batten down and prepare to ride out the storm
    N c. continue to navigate farther from the coast
    N d. always navigate towards the coast by the most direct route

1515: An aneroid barometer on a boat should always be __________.

    N a. located in an air-conditioned area
    N b. mounted in the passenger compartment
    N c. protected by a collision bulkhead
    Y d. permanently mounted

1674: The letter D in illustration D006NG represents the __________.

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

1692: The force resulting from the earth's rotation that causes winds to deflect to the right in the Northern Hemisphere and to the left in the Southern Hemisphere is called __________.

    N a. pressure gradient
    Y b. Coriolis effect
    N c. aurora borealis
    N d. ballistic deflection

1697: In the Northern Hemisphere, if the center of a high pressure area is due west of you, what wind direction would you expect?

    N a. South to west
    N b. South to east
    Y c. North to west
    N d. North to east

1781: While in port, you can follow the approach of a dangerous cyclonic storm by inspecting __________.

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

1874: Lighted white and orange buoys must show which color light?

    N a. Orange
    N b. Red
    N c. Alternating yellow and white
    Y d. White

1909: In the horizon system of coordinates what is equivalent to the equator on the Earth?

    N a. Prime vertical circle
    N b. Principal vertical circle
    N c. Parallels of altitude
    Y d. 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

2119: Which stock number indicates an NGA (NIMA) chart designed for fixing positions at sea and DR plotting while on a long voyage?

    Y a. WOAGN520
    N b. PILOT16
    N c. 16BCO16212
    N d. WOPZC5245

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

2144: Yesterday your chronometer read 02h 59m 58s at the 1500 GMT time tick. Today the chronometer reads 03h 00m 02s at the 1500 GMT time tick. What is the chronometer error?

    Y a. 02s fast
    N b. 03h 00m 02s fast
    N c. +3s
    N d. -3s

2159: Induced magnetism is found in __________.

    N a. hard iron
    Y b. soft iron
    N c. vertical iron only
    N d. horizontal iron only

2183: 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 D if the lock walls and piers are not awash?

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

2237: A lighted buoy to be left to starboard, when entering a U.S. port from seaward, shall have a __________.

    N a. light characteristic of Morse (A)
    N b. white light
    N c. green light
    Y d. red light

2290: Magnets in the binnacles of magnetic compasses are used to reduce the effect of __________.

    Y a. deviation
    N b. variation
    N c. local attraction
    N d. All of the above

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

2470: You are on course 344°T and take a relative bearing of a lighthouse of 090°. What is the true bearing to the lighthouse?

    N a. 016°
    Y b. 074°
    N c. 254°
    N d. 270°

2596: The abbreviation L.W.R.P. on the navigation maps means __________.

    Y a. low water reference plane
    N b. low winter runoff point
    N c. least water river plane
    N d. land wall reference point

2650: In the celestial equator system of coordinates what is equivalent to the colatitude of the Earth system of coordinates?

    N a. Coaltitude
    N b. Zenith distance
    Y c. Polar distance
    N d. Declination

2651: Low pressure disturbances which travel along the intertropical convergence zone are called __________.

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

2709: Under the IALA-B Buoyage System, when entering from seaward a lateral system buoy to be left to port may display which of the topmarks shown? (D046NG )

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

2882: While upbound through Memphis, the weather report on TV news indicates that a warm front is stationary over the Kentucky - Missouri - Tennessee areas. What weather conditions should you expect?

    N a. Strong, gusting winds from the NW with thundershowers
    N b. Light winds from the northeast with clear skies
    N c. A "blue norther"
    Y d. Southerly winds with steady rain; fog or overcast

2886: On mid-ocean waters, the height of a wind-generated wave is not affected by the __________.

    Y a. water depth exceeding 100 feet
    N b. fetch
    N c. wind's velocity
    N d. duration of the wind