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.


10: The wind at Frying Pan shoals has been northwesterly at an average velocity of 22 knots. The predicted set and drift of the rotary current are 125° at 0.6 knot. What current should you expect?


67: What is the definition of height of tide?


89: The GHA of the first point of Aries is 315° and the GHA of a planet is 150°. What is the right ascension of the planet?


151: Under the U.S. Aids to Navigation System, spherical buoys may be __________.

    N a. numbered
    Y b. lettered
    N c. lighted
    N d. All of the above

162: A chart with a scale of 1:80,000 would fall into the category of a __________.

    N a. sailing chart
    N b. general chart
    Y c. coastal chart
    N d. harbor chart

193: In using Loran-C, skywave reception gives greater range but is __________.

    N a. only accurate during daylight hours
    Y b. much less accurate
    N c. only accurate at twilight
    N d. more accurate than using ground waves

203: In any Loran-C chain, there are three or more stations transmitting pulses which radiate in all directions. One of the stations is the master station, and the others in the chain are the __________.

    N a. radio stations
    Y b. secondary stations
    N c. monitor stations
    N d. pulse stations

244: To make sure of getting the full advantage of a favorable current, you should reach an entrance or strait at what time in relation to the predicted time of the favorable current?

    N a. One hour after the predicted time
    N b. At the predicted time
    N c. 30 minutes before flood, one hour after an ebb
    Y d. 30 minutes before the predicted time

246: The consistent winds blowing from the horse latitudes to the doldrums are called the __________.

    N a. prevailing westerlies
    N b. polar easterlies
    Y c. trade winds
    N d. roaring forties

269: The wind at Frying Pan shoals has been south-southwesterly at an average velocity of 30 knots. The predicted set and drift of the rotary current are 232° at 0.8 knot. What current should you expect?

    N a. 065° at 1.2 knots
    N b. 092° at 1.3 knots
    N c. 139° at 0.6 knot
    Y d. 224° at 0.4 knot

340: Information about the direction and velocity of rotary tidal currents is found in the __________.

    N a. Mariner's Guide
    N b. Nautical Almanac
    N c. Tide Tables
    Y d. Tidal Current Tables

390: During the winter months, the southeast trade winds are __________.

    Y a. stronger than during the summer months
    N b. weaker than during the summer months
    N c. drier than during the summer months
    N d. wetter than during the summer months

415: If the Sun's observed altitude is 54°30', what is the zenith distance?

    Y a. 35°30'
    N b. 45°30'
    N c. 12°30'
    N d. 14°30'

439: If a weather bulletin shows the center of a low pressure system to be 100 miles due east of you, what winds can you expect in the Southern Hemisphere?

    Y a. South-southwesterly
    N b. North-northwesterly
    N c. South-southeasterly
    N d. North-northeasterly

498: What is an advantage of the magnetic compass aboard vessels?

    N a. Compass error is negligible at or near the earth's magnetic poles.
    N b. It does not have to be checked as often.
    Y c. It is reliable due to it's essential simplicity.
    N d. All points on the compass rose are readily visible.

514: What instrument measures wind velocity?

    N a. Hydrometer
    N b. Barometer
    N c. Psychrometer
    Y d. Anemometer

646: You have determined that you are in the right semicircle of a tropical cyclone in the Northern Hemisphere. What action should you take to avoid the storm?

    N a. Place the wind on the starboard quarter and hold that course.
    N b. Place the wind on the port quarter and hold that course.
    N c. Place the wind on the port bow and hold that course.
    Y d. Place the wind on the starboard bow and hold that course.

826: In the U.S., in which direction do air masses usually move?

    Y a. Easterly
    N b. Southerly
    N c. Northerly
    N d. Southwesterly

920: What is the average speed of the movement of a hurricane following the recurvature of its track?

    N a. 5 to 10 knots
    Y b. 20 to 30 knots
    N c. 40 to 50 knots
    N d. Over 60 knots

921: Under the IALA-B Buoyage System, a conical buoy will be __________.

    Y a. red in color
    N b. numbered with an odd number
    N c. left to port when entering from seaward
    N d. All of the above

965: In order for a star to be used for a sight at lower transit, the star must __________.

    Y a. be circumpolar
    N b. have a declination equal to or greater than your latitude
    N c. have a GHA of 180°
    N d. have the SHA equal to or less than the LHA

1031: While steaming north of the Irish coast, you sight a buoy which shows the light rhythm shown in illustration D028NG. How would you pass this buoy? (D028NG )

    N a. North of the buoy
    Y b. East of the buoy
    N c. South of the buoy
    N d. West of the buoy

1052: What is the approximate geographic range of Southwest Ledge Light, Connecticut, if your height of eye is 32 feet (9.8 meters)? Refer to "Reprints from the LIGHT LISTS AND COAST PILOTS" .

    Y a. 15.5 nm
    N b. 13.4 nm
    N c. 8.7 nm
    N d. 6.9 nm

1061: In waters where the cardinal system is used you would expect to find danger __________.

    N a. lying to the south of an eastern quadrant buoy
    Y b. lying to the south of a northern quadrant buoy
    N c. lying to the east of an eastern quadrant buoy
    N d. beneath or directly adjacent to the buoy

1084: As the temperature of an air mass decreases, the __________.

    N a. absolute humidity decreases
    Y b. relative humidity increases
    N c. specific humidity decreases
    N d. dew point rises

1084: As the temperature of an air mass decreases, the __________.

    N a. absolute humidity decreases
    Y b. relative humidity increases
    N c. specific humidity decreases
    N d. dew point rises

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

1134: The Earth's irregular heating is caused by __________.

    N a. the time of day
    N b. the seasons
    N c. geography
    Y d. All of the above

1263: The compass deviation changes as the vessel changes __________.

    N a. geographical position
    N b. speed
    Y c. heading
    N d. longitude

1323: The magnetic compass error which changes with the geographical location of your vessel is called __________.

    N a. deviation
    Y b. variation
    N c. compensation
    N d. differentiation

1331: When trying to sight a lighthouse you notice a glare from a town in the background. The range at which the light may be sighted due to this glare is __________.

    Y a. considerably reduced
    N b. increased slightly due to extra lighting
    N c. unchanged
    N d. increased if the light is red or green due to contrast with the glare

1370: Which type of cloud is indicated by the number 8? (D039NG )

    N a. Cumulonimbus
    N b. Altostratus
    N c. Cirrostratus
    Y d. Nimbostratus

1429: A celestial body will cross the prime vertical circle when the latitude is numerically __________.

    Y a. greater than the declination and both are of the same name
    N b. less than the declination and both are of the same name
    N c. greater than the declination and both are of contrary name
    N d. less than the declination and both are of contrary name

1518: Which publication requires infrequent corrections?

    N a. List of Lights
    N b. Coast Pilot
    Y c. Sailing Directions (Planning Guide)
    N d. Radio Navigational Aids

1536: What will NOT induce errors into a Doppler sonar log?

    Y a. Increased draft
    N b. Pitch
    N c. Roll
    N d. Change in trim

1574: Information about currents around Pacific Coast ports of the U.S. is found in the __________.

    N a. Nautical Almanac
    N b. Tide Tables
    Y c. Tidal Current Tables
    N d. Ocean Current Tables

1709: The Beaufort scale is used to estimate the __________.

    N a. wind direction
    N b. percentage of cloud cover
    Y c. wind speed
    N d. barometric 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

1734: The eye of the hurricane has __________.

    N a. very high barometric pressure
    N b. average barometric pressure
    Y c. the lowest barometric pressure
    N d. no change in barometric pressure

1818: In order to utilize the capacity of a lock to its maximum, pleasure craft are locked through with all of the following EXCEPT __________.

    N a. coal barges
    Y b. oil barges
    N c. sand barges
    N d. cement barges

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°

1968: The Earth has the shape of a(n) __________.

    N a. sphere
    Y b. oblate spheroid
    N c. spheroid of revolution
    N d. oblate eggoid

1976: The Moon is nearest to the Earth at __________.

    Y a. perigee
    N b. the vernal equinox
    N c. the new Moon
    N d. the full Moon

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

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

2224: By convention, the north seeking ends of a compass' magnets are colored __________.

    N a. black
    N b. blue
    Y c. red
    N d. white

2288: A mean sun is used as the reference for solar time for three reasons. Which reason is NOT a cause for use of a mean sun?

    N a. The motion of the apparent sun is along the ecliptic.
    Y b. Measurement of time is along the celestial equator.
    N c. The speed of the Earth's revolution is not constant.
    N d. There are variations in the Earth's rotational speed.

2336: The period of revolution of the Moon is __________.

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

2340: What is a "Special Warning"?

    N a. An urgent message concerning a vessel in distress
    N b. A weather advisory about unusual meteorological or oceanographic phenomena hazardous to vessels
    Y c. A broadcast disseminating an official government proclamation affecting shipping
    N d. A radio navigational warning concerning a particularly hazardous condition affecting navigation

2382: What causes geocentric parallax?

    N a. The varying distance between the Earth and Moon.
    Y b. The change in the Moon's position relative to the stars when viewed from the Earth's surface, as compared to the Earth's center.
    N c. The rapid change in declination of the Moon causes a rotational oscillation of its axis.
    N d. The nearness of the Moon causes an apparent increase in diameter as its altitude increases.

2428: If your vessel were proceeding up river (ascending), the port side of the channel would be marked according to the U. S. Aids to Navigation System on the Western Rivers by __________.

    Y a. green can buoys
    N b. red can buoys
    N c. green nun buoys
    N d. red nun buoys

2446: What is the equivalent of 47 min. 20 sec. in arc units?

    N a. 8°27'
    Y b. 11°50'
    N c. 13°42'
    N d. 13°56'

2636: You are ascending a river and exchanging navigational information via radiotelephone with a descending vessel. If the descending vessel advises you to "watch for the set" above point X, what would you expect to encounter above point X?

    N a. An increase in current velocity
    N b. Slack water
    N c. Shallow water
    Y d. A sideways movement of your vessel

2675: When you are steering on a pair of range lights and find the upper light is in line above the lower light, you should __________.

    N a. come left
    Y b. continue on the present course
    N c. come right
    N d. wait until the lights are no longer in a vertical line

2707: You will find information about the duration of slack water in the __________.

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

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

2875: A harbor chart could have a scale of __________.

    N a. not more than 1:25,000
    Y b. 1:35,000
    N c. 1:150,000
    N d. not less than 1:500,000

2889: On 29 June 1981 you observe a back sight of the upper limb of the Moon. The sextant altitude (hs) is 114°16.9'. The height of eye is 36 feet, and the index error is 2.0' off the arc. The horizontal parallax is 60.5'. What is the observed altitude (Ho)?

    N a. 66°23.8'
    N b. 66°04.4'
    N c. 66°00.4'
    Y d. 65°53.8'

2890: While passing through Memphis, the weather report on the TV news indicates that a cold front is crossing western Kentucky and Tennessee. Tomorrow's weather will be dominated by a high pressure area. What weather should you expect tomorrow?

    N a. Light, southerly winds; high humidity and possibly fog
    Y b. Moderate winds from the northwest, clear visibility and cooler temperatures
    N c. Low overcast; mild temperatures with light, steady rain or drizzle
    N d. Scattered clouds with light, southeasterly winds; high humidity and possibly fog

2969: A red triangular daymark marks __________.

    N a. the centerline of a navigable channel
    Y b. the starboard side of a channel
    N c. a prominent object of navigational interest that has no lateral significance
    N d. an area of a channel where passing another vessel is permitted

3117: With respect to automatic identification systems (AIS), which information is required to be broadcast every 1 to 10 seconds?

    Y a. Time stamp
    N b. IMO number
    N c. Type of vessel
    N d. Vessel's maximum displacement