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.


40: The predicted time that the flood 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 1600 and turn for 8 knots, at what point will you lose the ebb current?


82: On the west coast of North America, charted depths are taken from __________.


108: A position that is obtained by using two or more intersecting lines of position taken at nearly the same time, is a(n) __________.


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

201: What is a lighted safe water mark fitted with to aid in its identification?

    N a. Red and white retroreflective material
    Y b. A spherical topmark
    N c. A sequential number
    N d. A red and white octagon

257: Spring tides occur __________.

    N a. at the start of spring, when the Sun is nearly over the equator
    N b. only when the Sun and Moon are on the same side of the Earth and nearly in line
    N c. when the Sun and Moon are at approximately 90° to each other as seen from the Earth
    Y d. when the Sun, Moon, and Earth are nearly in line, in any order

316: According to Buys Ballot's law, when an observer in the Northern Hemisphere experiences a northwest wind, the center of low pressure is located to the __________.

    Y a. northeast
    N b. west-southwest
    N c. northwest
    N d. south-southeast

345: A navigator fixing a vessel's position by radar __________.

    N a. should never use radar bearings
    N b. should only use radar bearings when the range exceeds the distance to the horizon
    Y c. can use radar information from one object to fix the position
    N d. must use information from targets forward of the beam

399: Where will you find information about the duration of slack water?

    N a. American Practical Navigator
    N b. Sailing Directions
    N c. Tide Tables
    Y d. Tidal Current Tables

434: The purpose of the "set" hand on an aneroid barometer is to __________.

    N a. adjust the barometer
    Y b. indicate any change in the reading of the barometer
    N c. provide a correction for height above sea level
    N d. provide a correction for temperature changes

470: You are underway on course 120°T and can make 12 knots. The eye of a hurricane bears 150°T at 120 miles. The hurricane is on course 295° at 20 knots. What course should you steer at 12 knots to have the maximum CPA?

    N a. 312°
    N b. 330°
    Y c. 348°
    N d. 001°

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

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

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

577: Your vessel has a draft of 24 feet. On 7 April 1983 you wish to pass over a temporary obstruction near Lovell Island, MA, that has a charted depth of 22 feet. Allowing for a safety margin of 3.1 feet under your keel, what is the earliest time after 0100 EST (ZD +5) that this passage can be made?

    N a. 0248
    N b. 0304
    Y c. 0342
    N d. 0356

589: What is the index error of sextant D? (D050NG )

    N a. 7'10" on the arc
    N b. 6'50" on the arc
    N c. 3'00" on the arc
    Y d. 2'10" on the arc

601: White and orange buoys, if lighted, show which color light?

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

706: A steep barometric gradient indicates __________.

    N a. calms
    N b. light winds
    Y c. strong winds
    N d. precipitation

762: Chart correction information is NOT disseminated through the __________.

    N a. Summary of Corrections
    N b. Local Notice to Mariners
    N c. Daily Memorandum
    Y d. Chart Correction Card

813: At the magnetic equator there is no induced magnetism in the vertical soft iron because __________.

    N a. the lines of force cross the equator on a 0°-180° alignment
    N b. the quadrantal error is 0°
    Y c. there is no vertical component of the Earth's magnetic field
    N d. the intercardinal headings have less than 1° error

909: What is the average speed of movement of a hurricane prior to recurvature?

    N a. 4 to 6 knots
    N b. 6 to 8 knots
    Y c. 10 to 12 knots
    N d. 15 to 20 knots

977: In the Sargasso Sea there are large quantities of seaweed and no well defined currents. This area is located in the __________.

    Y a. Central North Atlantic Ocean
    N b. Caribbean Sea
    N c. Western North Pacific Ocean
    N d. area off the west coast of South America

997: A coastal current __________.

    N a. is generated by waves striking the beach
    Y b. flows outside the surf zone
    N c. flows in a circular pattern
    N d. is also known as a longshore current

1028: At what angle to the isobars do surface winds blow over the open sea?

    N a. About 90°
    N b. About 50°
    N c. About 25°
    Y d. About 15°

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

1116: When a cold air mass and a warm air mass meet, and there is no horizontal motion of either air mass, it is called a(n) __________.

    N a. cold front
    N b. occluded front
    Y c. stationary front
    N d. warm front

1154: The speed at which an ocean wave system advances is called __________.

    N a. wave length
    N b. ripple length
    Y c. group velocity
    N d. wave velocity

1157: How many slack tidal currents usually occur each day on the east coast of the United States?

    N a. One
    N b. Two
    N c. Three
    Y d. Four

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

1317: What will be the velocity and direction of the tidal current at Mobile River Entrance, AL, at 0915 CDT (ZD +5) on 13 May 1983?

    N a. 0.1 knot at 333°T
    Y b. 0.3 knot at 333°T
    N c. 0.7 knot at 151°T
    N d. 1.8 knots at 025°T

1353: The difference in degrees between true north and magnetic north is called __________.

    Y a. variation
    N b. deviation
    N c. drift
    N d. compass error

1355: The parallax of the Moon is greatest when the Moon is __________.

    N a. in the zenith at perigee
    N b. on the horizon at apogee
    N c. at its maximum altitude at apogee
    Y d. on the horizon at perigee

1355: The parallax of the Moon is greatest when the Moon is __________.

    N a. in the zenith at perigee
    N b. on the horizon at apogee
    N c. at its maximum altitude at apogee
    Y d. on the horizon at perigee

1420: the position labeled "E" was plotted because __________. (D051NG )

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

1467: Determine the time after 0730 EST (ZD +5) when the velocity of the current will be 2.1 knots on 26 March 1983, at Fort Pulaski, GA.

    N a. 0802
    N b. 0812
    N c. 0821
    Y d. 0840

1696: Two well-developed high pressure areas may be separated by a __________.

    N a. hill of low pressure
    Y b. trough of low pressure
    N c. valley of low pressure
    N d. ridge of low pressure

1717: A tropical storm is a tropical cyclone that generates winds of __________.

    N a. between 20 and 33 knots
    Y b. between 34 and 63 knots
    N c. over 63 knots
    N d. None of the above

1725: Your present weather is sunny with a steady barometer. A low swell approaches your vessel from the south with crests passing at relatively long periods of about four per minute. This usually indicates __________.

    N a. a warm front from the south
    Y b. a tropical cyclone south of your vessel
    N c. a hurricane about 100 miles south of your vessel and heading in your direction
    N d. an extra-tropical cyclone

1746: Swells that have outrun the storm are produced in the __________.

    N a. left front quadrant
    Y b. right front quadrant
    N c. rear
    N d. directly ahead on the storms projected track

1759: Which magnetic compass corrector(s) can be set while the vessel is on a heading of magnetic north or magnetic south?

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

1784: If your vessel were proceeding down river (descending), a green square marker with a green reflector border on the right bank would be a __________.

    N a. mile board
    N b. dredging mark
    Y c. passing daymark
    N d. crossing daymark

1862: What is the relative bearing of an object broad on the starboard quarter?

    N a. 090°
    N b. 105°
    Y c. 135°
    N d. 150°

1875: The position labeled "E" was plotted because __________. (D051NG )

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

1906: In the horizon system of coordinates what is equivalent to latitude on the Earth?

    Y a. Altitude
    N b. Zenith
    N c. Declination
    N d. Zenith distance

1942: In the horizon system of coordinates what is equivalent to the declination of the equator system?

    N a. Nadir
    N b. Azimuth angle
    Y c. Altitude
    N d. Zenith distance

2024: In the North Sea area, you sight a buoy with a quick light showing 3 flashes every 10 seconds. Which topmark in illustration D030NG would be fitted to this buoy under the IALA Buoyage Systems? (D030NG )

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

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

2207: Yesterday your chronometer read 11h 59m 58s at the 1200 GMT time tick. Today your chronometer reads 12h 00m 00s at the 1200 time tick. What is the chronometer rate?

    N a. Nil
    N b. 12h
    Y c. +2s
    N d. -2s

2309: The plane of the ecliptic is inclined to the plane of the celestial equator by what angle?

    N a. 00°23'
    Y b. 23°27'
    N c. 45°00'
    N d. 90°00'

2452: The permanent magnetism of a vessel may change in strength due to __________.

    N a. the nature of the cargo being carried
    N b. changes in heading
    Y c. major structural repair
    N d. All of the above

2494: You must construct a Mercator plotting sheet on a piece of paper measuring 24" by 30". The area includes latitude 28°N to 35°N and longitude 175°E to 178°W. Allow a three-quarter 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?

    N a. 3.40 inches
    Y b. 3.22 inches
    N c. 3.03 inches
    N d. 2.91 inches

2654: What is the equivalent of 5°54' in time units?

    N a. 20 min. 16 sec.
    Y b. 23 min. 36 sec.
    N c. 25 min. 54 sec.
    N d. 30 min. 27 sec.

2682: Sidereal time is used by navigators when __________.

    N a. used with the equation of time
    Y b. used in the form of LHA Aries
    N c. calculating the time of moonrise
    N d. determining local apparent time

2832: The Light List indicates that a dayboard is a type MR. You should __________.

    Y a. leave it on either side
    N b. look for the other dayboard forming the range
    N c. look for an all red daymark
    N d. check to enter the correct channel at this junction daymark

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

2849: You take a bearing of 086° of a lighthouse. What bearing of another object would give the best fix?

    Y a. 000°
    N b. 066°
    N c. 112°
    N d. 271°

2852: A daymark warning of a danger will have the shape indicated by which letter? (D045NG )

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

2944: The height of a wave is the vertical distance __________.

    N a. from the still water plane to the crest
    N b. from the still water plane to the trough
    Y c. from crest to trough
    N d. between water levels at one-quarter of the wave's length

2959: Vessels required to have an Automatic Radar Plotting Aid must have a device to indicate the __________.

    N a. time of the next navigational satellite
    N b. distance to the next port
    Y c. speed of the vessel over the ground or through the water
    N d. None of the above

3056: A position obtained by applying ONLY your vessel's course and speed to a known position is a __________.

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

3067: Which of the following are data layer categories to be displayed on ECDIS?

    N a. ECDIS warnings and messages
    N b. Hydrographic Office data
    N c. Notice to Mariners information
    Y d. All of the above