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.


25: You are in LONG 144°E. The date is 6 February, and the zone time is 0800. The Greenwich date and time are __________.


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


324: Index error of a sextant is primarily caused by __________.


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

422: If you are sailing from the East Coast of the United States to the Caribbean Sea, which publication would contain information on weather, currents, and storms?

    N a. Sailing Charts of the Caribbean Sea
    Y b. Pilot Charts of the North Atlantic
    N c. Light Lists, Atlantic and Gulf Coast
    N d. Tidal Current Tables

427: On 23 March 1983, at Kingston Point, NY, what is the earliest time after 1700 EST (ZD +5) that the predicted tide will be +2.0 feet?

    N a. 1730
    N b. 1800
    Y c. 1854
    N d. 2030

427: On 23 March 1983, at Kingston Point, NY, what is the earliest time after 1700 EST (ZD +5) that the predicted tide will be +2.0 feet?

    N a. 1730
    N b. 1800
    Y c. 1854
    N d. 2030

432: When using a Lambert conformal chart in high latitudes, angles such as bearings are measured in reference to __________.

    N a. the meridian through the object of the bearing
    Y b. the meridian through the ship's position
    N c. the meridian midway between the ship and the object
    N d. any meridian

457: Find the height of the tide at Port Wentworth, GA, on 5 October 1983, at 1840 DST (ZD +4).

    N a. 3.0 feet
    N b. 3.5 feet
    N c. 4.0 feet
    Y d. 4.4 feet

489: You are anchored in the Aleutian Island chain and receive word that a tsunami is expected to strike the islands in six hours. What is the safest action?

    Y a. Get underway and be in deep, open-ocean water when the tsunami arrives.
    N b. Increase the scope of the anchor cable and drop the second anchor underfoot at short stay.
    N c. Get underway and be close inshore on the side of the island away from the tsunami.
    N d. Plant both anchors with about a 60° angle between them, and let out a long scope to each anchor.

613: Your radar indicates a target; however, there is no visible object at the point indicated. A large mountain, approximately 50 miles away on the same bearing as the target, is breaking the horizon. You should suspect the radar target is caused by __________.

    N a. a submerged submarine
    Y b. ducting
    N c. sub-refraction
    N d. ionospheric skip waves

617: You are bound for the Chelsea docks in the Hudson River. The Captain wants to arrive at the docks at the first slack water on 28 July 1983. You are keeping daylight saving time. What time should you be at the docks?

    Y a. 0215
    N b. 0530
    N c. 0811
    N d. 0911

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

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

669: It is desirable that a vessel encountering hurricane or typhoon conditions sends weather reports to the closest meteorological service at least every __________.

    N a. hour
    Y b. 3 hours
    N c. 6 hours
    N d. 8 hours

681: You sight a spar buoy with the top mark shown in the illustration. You must __________. (D027NG )

    N a. pass to the east of the buoy
    N b. pass to the south of the buoy
    N c. pass to the north of the buoy
    Y d. keep well clear of the buoy and pass on either side

691: Of the four light characteristics shown which one does NOT represent a safe water mark of the IALA Buoyage System? (D019NG )

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

707: Set of the current is __________.

    N a. its velocity in knots
    N b. direction from which it flows
    N c. estimated current
    Y d. direction towards which it flows

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.

821: In addition to monitoring channel 16, all Corps of Engineer locks may use as working channels __________.

    N a. 06, 12 and 22A
    N b. 01A, 05A and 07A
    Y c. 12, 13 and 14
    N d. 14, 24 and 28

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

925: Your vessel is at the equator at midnight on 1 January, and a star is observed rising. At what time will this same star rise on 1 February, assuming your vessel's location is still at the equator?

    N a. 2208
    N b. 2110
    Y c. 2158
    N d. 2317

947: The cold ocean current which meets the warm Gulf Stream between latitudes 40° and 43°N to form the "cold wall" is called the __________.

    N a. North Cape Current
    Y b. Labrador Current
    N c. Greenland Current
    N d. North Atlantic Current

991: You are underway in the North Sea on course 328°T when you sight a buoy broad on your port bow. You are in the best navigable water if the buoy __________.

    N a. has a topmark of two cones with points down
    N b. is a western quadrant buoy
    N c. is painted yellow on the top half and black on the bottom
    Y d. exhibits a light with the characteristic of VQ(3)5s

1001: While steaming in English waters on course 280°T, you sight a buoy showing a very quick-flashing (VQ) white light well to port. Maintaining course, you sight another buoy showing a quick-flashing (Q) white light. You should pass __________.

    Y a. north of the buoy
    N b. west of the buoy
    N c. east of the buoy
    N d. south of the buoy

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

1073: Chart legends printed in capital letters show that the associated landmark is __________.

    N a. inconspicuous
    N b. a radio transmitter
    Y c. conspicuous
    N d. a government facility or station

1088: Which statement about an estimated position is TRUE?

    N a. It is more reliable than a fix based on radar bearings.
    Y b. It may be based on a single LOP or questionable data.
    N c. When a 3-LOP fix plots in a triangle, the center of the triangle is the estimated position.
    N d. It is usually based on soundings.

1093: The Flinders bar on a magnetic compass compensates for the __________.

    Y a. induced magnetism in vertical soft iron
    N b. induced magnetism in horizontal soft iron
    N c. permanent magnetism in ship's steel
    N d. vessel's inclination from the vertical

1118: When entering from seaward, a buoy displaying a single-flashing red light indicates __________.

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

1262: A safe water daymark has what shape?

    N a. Triangular
    N b. Diamond
    N c. Circular
    Y d. Octagonal

1359: The distance in longitude from the intersection of a great circle and the equator to the lower vertex is how many degrees of longitude?

    N a. 45°
    Y b. 90°
    N c. 135°
    N d. 180°

1510: During daylight savings time the meridian used for determining the time is located farther __________.

    N a. west
    Y b. east
    N c. east in west longitude and west in east longitude
    N d. west in west longitude and east in east longitude

1540: You are sailing south on the Intracoastal Waterway (ICW) when you sight a green can buoy with a yellow square painted on it. Which of the following is TRUE?

    N a. You should pass the buoy close aboard on either side.
    N b. The buoy marks the end of the ICW in that area.
    Y c. You should leave the buoy to port.
    N d. The yellow square is retroreflective material used to assist in sighting the buoy at night.

1556: The vertical distance from the tidal datum to the level of the water is the __________.

    N a. range of tide
    N b. charted depth
    Y c. height of tide
    N d. actual water depth

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

1624: A psychrometer has two thermometers that provide dry bulb and wet bulb temperatures. By comparing these two temperature readings with a set of tables you can determine the __________.

    N a. atmospheric pressure
    N b. wind speed
    Y c. relative humidity and dew point
    N d. wind chill factor

1633: To find a magnetic compass course from a true course you must apply __________.

    Y a. deviation and variation
    N b. deviation
    N c. variation
    N d. magnetic anomalies (local disturbances)

1721: A storm's track is characterized by all of the following except __________.

    N a. the direction the storm has come from
    N b. the direction in which the storm is moving
    Y c. the speed at which the storm is moving
    N d. the path taken by the storm

1761: Chart legends which indicate a conspicuous landmark are printed in __________.

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

1803: The difference between the DR position and a fix, both of which have the same time, is caused by __________.

    N a. variation
    N b. deviation
    Y c. current
    N d. leeway

1930: The phase correction should be applied to sights of Venus and Mars __________.

    N a. during day time observations only
    Y b. during twilight observations only
    N c. at all times
    N d. when observed at altitudes of less than 25°

1962: When outbound from a U.S. port, a buoy displaying a flashing red light indicates __________.

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

2061: Fog is likely to occur when there is little difference between the dew point and the __________.

    N a. relative humidity
    Y b. air temperature
    N c. barometric pressure
    N d. absolute humidity

2087: The Light List indicates that a light has a nominal range of 20 miles and is 52 feet (16 meters) high. If the visibility is 20 miles and your height of eye is 20 feet (6 meters), at what approximate distance will you sight the light?

    N a. 33.0 nm
    N b. 20.0 nm
    Y c. 13.5 nm
    N d. 8.5 nm

2141: What lights would you see on the Illinois water way when any wickets of the dam or bear traps are open, or partially open, which may cause a set in the current conditions in the upper lock approach?

    N a. Red over green
    N b. Green over red
    Y c. Red over amber (yellow)
    N d. Green over amber (yellow)

2226: Upper limb observations of the Moon are used more frequently than those of the Sun because of the location of the Moon in the sky and the __________.

    N a. lesser distance between the Earth and the Moon
    Y b. phase of the Moon
    N c. rapid change in declination of the Moon
    N d. effects of augmentation and horizontal parallax

2256: The constellation that contains Polaris is __________.

    N a. Orion
    N b. Cassiopeia
    Y c. Ursa Minor
    N d. Corona Borealis

2259: A vessel is heading magnetic northwest and its magnetic compass indicates a heading of 317°. What action should be taken to remove this error during compass adjustment?

    N a. If the quadrantal spheres are out as far as possible replace them with smaller spheres.
    N b. If the quadrantal spheres are in as far as possible remove one of the spheres.
    N c. If the quadrantal spheres are in as far as possible replace them with smaller spheres.
    Y d. If the quadrantal spheres are out as far as possible, move the quadrantal spheres in.

2269: One of the factors which affects the circulation of ocean currents is __________.

    N a. humidity
    Y b. varying densities of water
    N c. vessel traffic
    N d. the jet stream

2284: Bellatrix is found in what constellation?

    N a. Canis Minor
    N b. Gemini
    N c. Taurus
    Y d. Orion

2294: What celestial body may sometimes be observed in daylight?

    N a. New Moon
    N b. Saturn
    N c. Sirius
    Y d. Venus

2351: A position obtained by applying ONLY your vessel's course and speed to a known position is a __________.

    N a. running fix
    N b. probable position
    N c. fix
    Y d. dead-reckoning position

2388: The reference point for determination of GMT is the passage of the mean sun over what line?

    N a. First point of Aries
    N b. Observer's meridian
    N c. 0° longitude
    Y d. 180° longitude

2419: A backlash below a lock is defined as a __________.

    N a. current setting your vessel on the wall
    N b. current setting into the lock chamber
    Y c. an eddy working along the lower guide wall
    N d. current setting counterclockwise

2479: The equation of time measures the __________.

    N a. difference between local apparent time and Greenwich apparent time
    N b. longitude in time units
    N c. difference between sidereal time and local time at the Greenwich meridian
    Y d. time between the passage of the mean sun and the apparent sun over a meridian

2498: The light characteristic of flashing is used in the Aids to Navigation System on the Western Rivers for lights on __________.

    Y a. the right descending bank
    N b. the left descending bank
    N c. preferred channel buoys
    N d. daymarks with no lateral significance

2687: The letter B in illustration D006NG represents the __________.

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

2741: A general chart could have a scale of __________.

    Y a. 1:200,000
    N b. 1:1,000,000
    N c. 1:50,000
    N d. not more than 1:25,000

2958: Drawbridges equipped with radiotelephones display a __________.

    N a. day signal of a yellow diamond marked with the call sign
    N b. white sign with the number 16 and the call sign on it
    N c. black and white diamond marked with RT 16
    Y d. blue and white sign showing the radio's channels

3057: IN REGION A of the IALA Buoyage System, when entering from seaward, the starboard side of a channel would be marked by a __________.

    Y a. green conical buoy
    N b. green can buoy
    N c. red can buoy
    N d. red conical buoy