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.


52: The reference datum used in determining the heights of land features on most charts is __________.


60: The predicted time that the ebb begins at the entrance to Delaware Bay is 1526. You are anchored off Chestnut St. in Philadelphia. If you get underway bound for sea at 1630 and turn for 12 knots, at what point will you lose the flood current?


137: Priming of the tides occurs __________.


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

240: 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
    N b. when there is a following current
    Y c. at slack water
    N d. at flood

263: Loran-C uses the multiple pulse system because __________.

    N a. less signal energy is necessary for receiver operation
    Y b. more signal energy is available at the receiver
    N c. it significantly increases the peak power
    N d. it increases the signal capacity

280: Under the U.S. Aids to Navigation System, a lighted buoy with a spherical topmark marks __________.

    N a. the port side of the channel
    Y b. safe water
    N c. a hazard to navigation
    N d. the position of underwater cables

361: As your vessel is heading southward along the east coast of the United States, you encounter a buoy showing a red flashing light. How should you pass this buoy?

    N a. Pass it about 50 yards off on either side.
    Y b. Leave it to your starboard.
    N c. Leave it to your port.
    N d. Pass it well clear on either side.

476: Tropical cyclones normally form within which of the following belts of latitude?

    Y a. 5° to 15°
    N b. 15° to 30°
    N c. 30° to 45°
    N d. 45° to 60°

504: Barometer readings in weather reports are given in terms of pressure at __________.

    Y a. sea level
    N b. Washington, D.C.
    N c. the weather station
    N d. the broadcasting station

541: A yellow buoy may mark a(n) __________.

    N a. wreck
    N b. shoal area
    Y c. anchorage area
    N d. middle ground

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'

566: You are attempting to locate your position relative to a hurricane in the Northern Hemisphere. If the wind direction remains steady, but with diminishing velocity, you are most likely __________.

    N a. in the right semicircle
    N b. in the left semicircle
    N c. on the storm track ahead of the center
    Y d. on the storm track behind the center

574: If your mercurial barometer reads 30.50 inches (1033 millibars) and the temperature is 56°F (13°C), what is the correct reading at 55°N, 150°W?

    N a. 30.42 inches (1030 millibars)
    Y b. 30.45 inches (1031 millibars)
    N c. 30.50 inches (1032 millibars)
    N d. 30.53 inches (1033 millibars)

606: Early indications of the approach of a hurricane may be all of the following EXCEPT __________.

    Y a. short confused swells
    N b. gradually increasing white clouds (mare's tails)
    N c. pumping barometer
    N d. continuous fine mist-like rain

630: What kind of weather would you expect to accompany the passage of a tropical wave?

    Y a. Heavy rain and cloudiness
    N b. Good weather
    N c. A tropical storm
    N d. Dense fog

657: Current refers to the __________.

    N a. vertical movement of the water
    Y b. horizontal movement of the water
    N c. density changes in the water
    N d. None of the above

677: A swift current occurring in a narrow passage connecting two large bodies of water, which is produced by the continuously changing difference in height of tide at the two ends of the passage, is called a __________.

    Y a. hydraulic current
    N b. rectilinear current
    N c. rotary current
    N d. harmonic current

689: What is the index error of sextant C? (D050NG )

    Y a. 0'20" on the arc
    N b. 1'00" on the arc
    N c. 2'00" on the arc
    N d. 5'10" on the arc

721: Under the IALA Buoyage System, a red and white vertically-striped buoy would NOT indicate __________.

    N a. a landfall
    Y b. the extreme end of an islet
    N c. a mid-channel
    N d. a center line

797: Which statement is TRUE concerning the current of the Gulf Stream?

    N a. It reaches its daily maximum speed a few hours before the transit of the Moon.
    N b. It is slower at the time of neap tides than at spring tides.
    N c. When the Moon is at its maximum declination the stream is narrower than when the Moon is on the equator.
    Y d. Variations in the trade winds affect the current.

884: Which cloud type is normally associated with thunderstorms?

    N a. Cirrus
    N b. Stratus
    N c. Cumulus
    Y d. Cumulonimbus

937: The north equatorial current flows to the __________.

    N a. east
    N b. northeast
    N c. southwest
    Y d. west

955: The line of position determined from a sight with an observed altitude (Ho) of 88°45.0' should be __________.

    N a. reduced to the meridian and plotted as a latitude line
    N b. calculated as a longitude line
    N c. plotted by using an intercept from an assumed position
    Y d. plotted as an arc around the GP of the body

998: The navigable semicircle of a tropical storm in the South Indian Ocean is located on which side of the storm's track?

    N a. Rear
    N b. Front
    N c. Left
    Y d. Right

1014: Relative humidity is the percentage of water vapor that is in the air as compared to the maximum amount it can hold at __________.

    N a. a specific barometric pressure
    Y b. a specific temperature
    N c. a specific wind speed
    N d. any time

1032: What is the approximate geographic range of Point Judith Light, Rhode Island, if your height of eye is 62 feet (18.9 meters)? Refer to "Reprints from the LIGHT LISTS AND COAST PILOTS" .

    N a. 9.6 nm
    N b. 16.5 nm
    Y c. 18.6 nm
    N d. 20.7 nm

1046: The probability of a sudden wind may be foretold by __________.

    N a. a partly cloudy sky
    N b. an overcast sky
    Y c. a fast approaching line of dark clouds
    N d. the formation of cumulus clouds in the sky

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.

1094: A light, feathery deposit of ice caused by the sublimation of water vapor directly into the crystalline form, on objects whose temperatures are below freezing, is called __________.

    N a. dew
    Y b. frost
    N c. glaze
    N d. snow

1185: An orange and white buoy with a rectangle on it displays __________.

    N a. directions
    N b. distances
    N c. locations
    Y d. All of the above

1430: The Light List indicates that a light has a nominal range of 14 miles and is 42 feet high (12.8 meters). If the visibility is 6 miles and your height of eye is 20 feet (6.1 meters), at what approximate distance will you sight the light?

    N a. 20.1 miles
    Y b. 10.0 miles
    N c. 7.6 miles
    N d. 6.0 miles

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

1459: In a tropical cyclone, in the Northern Hemisphere, a vessel hove to with the wind shifting counterclockwise is __________.

    N a. ahead of the storm center
    N b. in the dangerous semicircle
    Y c. in the navigable semicircle
    N d. directly in the approach path of the storm

1497: When drawing a weather map and an isobar crosses a front, the isobar is drawn __________.

    N a. perpendicular to the front
    Y b. kinked and pointing away from the low
    N c. kinked and pointing towards the low
    N d. kinked and pointing towards the high for a warm front only

1505: At 0000 you fix your position and change course to 090°T. At 0030 you again fix your position and it is 0.5 mile east of your DR. Which statement is TRUE?

    Y a. The current is easterly.
    N b. The drift is 0.5 knot.
    N c. You should alter course to the right to regain the track line.
    N d. The current is perpendicular to your track line.

1634: A lighted buoy to be left to starboard, when entering a U.S. port from seaward, shall have a __________.

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

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

1736: Which statement is FALSE concerning the dangerous semicircle of a hurricane?

    N a. The actual wind speed is increased by the forward movement of the storm along its track
    N b. the direction of the wind and the sea might carry a vessel directly into the storm's path
    N c. The seas are higher
    Y d. The rain is heavier

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

1866: What term is used to describe a tank barge constructed with the structural framing inside the cargo tank and the side shell plating containing the cargo?

    Y a. Single hull
    N b. Shell plated
    N c. Hopper type
    N d. Independent tank

1887: The Light List indicates that a light has a nominal range of 10 miles and is 11 feet high. If the visibility is 15 miles and your height of eye is 20 feet, at what approximate distance will you sight the light?

    N a. 12.0 miles
    N b. 11.0 miles
    N c. 10.0 miles
    Y d. 9.0 miles

2020: A vessel heading ENE is on a course of __________.

    N a. 022.5°
    N b. 045.0°
    Y c. 067.5°
    N d. 090.0°

2092: Descending boats, while awaiting their turn to enter a lock, shall NOT block traffic from the lock. They shall be above the lock by at LEAST __________.

    N a. 100 feet
    N b. 200 feet
    N c. 300 feet
    Y d. 400 feet

2098: Which magnetic compass corrector(s) can be set while the vessel is on a heading of magnetic east or magnetic west?

    N a. Quadrantal spheres
    N b. Heeling magnets
    Y c. Fore-and-aft magnets
    N d. Athwartships magnets

2102: The subregions of the United States Gulf and East Coasts are numbered 11, 12 and 13 within the chart numbering system. Which chart number indicates a chart for either the Gulf or East Coast?

    N a. 21214
    Y b. 11314
    N c. 14313
    N d. 14114

2124: You must draw a plotting sheet covering latitudes 45°N to 49°N and longitudes 179°E to 178°W. If the distance between latitude 45°N to 49°N is 20 inches, what is the distance between the meridians of 1° of longitude?

    N a. 2.9 inches
    N b. 3.2 inches
    Y c. 3.4 inches
    N d. 3.7 inches

2202: 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°. What action should be taken?

    N a. Adjust the compass with the athwartships magnets until the compass reads 264°.
    Y b. Adjust the compass with the fore-and-aft magnets until the compass reads 273°.
    N c. Adjust the compass with the quadrantal spheres until the compass reads 270°.
    N d. Adjust the compass with the athwartships magnets until the compass reads 273°.

2242: A vessel is heading magnetic north and its magnetic compass indicates a heading of 356°. Which action should be taken to remove this error during compass adjustment?

    Y a. If the red ends of the magnets are to port you should lower the athwartships tray.
    N b. If the red ends of the magnets are aft you should raise the fore-and-aft tray.
    N c. If the blue ends of the magnets are to port, and the athwartships tray is at the top, you should remove some of the magnets.
    N d. If the blue ends of the magnets are aft you should raise the fore-and-aft tray.

2298: The period of rotation of the Moon on its axis is __________.

    N a. about 19 years
    N b. 365 days
    Y c. about 27.3 days
    N d. 24 hours

2448: What is the equivalent of 37 min. 32 sec. in arc units?

    N a. 4°47'
    N b. 6°38'
    N c. 7°41'
    Y d. 9°23'

2466: On the Western Rivers, a vessel crossing a river must __________.

    N a. only keep out of the way of a power-driven vessel descending the river
    N b. keep out of the way of any vessel descending the river
    Y c. keep out of the way of a power-driven vessel ascending or descending the river
    N d. keep out of the way of any vessel ascending or descending the river

2602: The lunar day is also known as the __________.

    N a. lunitidal interval
    N b. vulgar establishment of the port
    N c. nodal day
    Y d. tidal day

2627: Stormy weather is usually associated with regions of __________.

    N a. high barometric pressure
    Y b. low barometric pressure
    N c. steady barometric pressure
    N d. changing barometric pressure

2652: The dividing meridian between zone descriptions -10 and -11 is __________.

    N a. 135°30'E
    N b. 145°00'E
    N c. 150°00'E
    Y d. 157°30'E

2679: Under the U.S. Aids to Navigation System on the Western Rivers, a daymark on the right descending bank will __________.

    Y a. be green
    N b. have an odd number
    N c. indicate the gage reading
    N d. have yellow retroreflective markings

2712: A bold reef is a reef __________.

    N a. with part of it extending above the water
    Y b. that can be detected by water turbulence
    N c. that drops off sharply
    N d. perpendicular to the current

2884: The pictures shown represent the geographic location of a vessel and the radar presentation at the same time. Which statement is TRUE? (D011NG )

    Y a. Ship No. 1 does not appear as an individual target due to the effect of beam width.
    N b. Small island is not detected due to the multiple echo effect from the mountain.
    N c. A tangent bearing of the headland to the south-southeast is corrected by subtracting one-half of the beam width.
    N d. Ship No. 2 is not detected due to the side lobe effect of radar reflecting from the mountain.

2994: You take a bearing of 313° and 076° of two objects. Which bearing of a third object will give the best fix?

    Y a. 014°
    N b. 133°
    N c. 255°
    N d. 339°

3118: With respect to automatic identification systems (AIS), which information is required to be broadcast every 1 to 10 seconds?

    N a. Call sign and IMO number
    Y b. Course over ground and MMSI
    N c. MMSI number and call sign
    N d. Route Plan and navigational status