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?


6: Wind velocity varies __________.


130: The distance between the surface of the water and the tidal datum is the __________.


169: You want to transit Hell Gate on 23 July 1983. What is the period of time around the AM (ZD +4) slack before ebb when the current will be less than 0.5 knot?

    Y a. 0939 to 0957
    N b. 0943 to 0953
    N c. 0844 to 0852
    N d. 0348 to 0356

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

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

212: Which aid is NOT marked on a chart with a magenta circle?

    N a. Radar station
    N b. Radar transponder beacon
    N c. Radio beacon
    Y d. Aero light

255: On March 17, at 0500 zone time, you cross the 180th meridian steaming eastward to west longitude. What is your local time?

    N a. You are in -12 time zone.
    N b. It is 1700, March 18.
    Y c. It is 0500, March 16.
    N d. It is 0500, March 18.

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

311: You are steaming southward along the west coast of the United States when you encounter a buoy showing a flashing red light. The buoy should be left on __________.

    N a. the vessel's starboard side
    Y b. the vessel's port side
    N c. either side close aboard
    N d. either side well clear

360: The Illustration shows the symbols used on radio facsimile weather charts. The symbol indicated at letter "M" represents __________. (D042NG )

    N a. rain
    Y b. snow
    N c. hail
    N d. ice

478: The velocity of the apparent wind can be more than the true wind, and come from the same direction, if certain conditions are present. One condition is that the __________.

    N a. ship's speed must be less than the true wind velocity
    N b. true wind must be from dead astern
    N c. true wind velocity must be faster than the ship's speed
    Y d. true wind must be from dead ahead

545: The arc of a great circle which passes through the body and celestial poles is part of the __________. (D007NG )

    Y a. hour circle
    N b. diurnal circle
    N c. observer's meridian
    N d. altitude circle

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

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

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

627: You are on a coastwise voyage bound for Marcus Hook, PA. Your speed is 15 knots. You wish to use the flood tide to facilitate docking starboard side to, heading seaward. To have the most favorable tide throughout, you should time your arrival at the entrance to Delaware Bay __________.

    N a. for 1 hour before flood begins
    N b. for 1 hour after flood begins
    Y c. for 3 hours after flood begins
    N d. for 1 hour before ebb begins

658: Monsoons are characterized by __________.

    N a. light, variable winds with little or no humidity
    N b. strong, gusty winds that blow from the same general direction all year
    Y c. steady winds that reverse direction semiannually
    N d. strong, cyclonic winds that change direction to conform to the passage of an extreme low pressure system

710: What is the FIRST sign of the existence of a well developed tropical cyclone?

    N a. Gale force winds from the north
    Y b. An unusually long ocean swell
    N c. Steep, short-period waves and light wind
    N d. Thunderstorms and higher than usual humidity

828: The true wind has been determined to be from 210°T, speed 12 knots. You desire the apparent wind to be 30 knots from 10° on the port bow. What course must you steer, and what speed must you make for this to occur?

    Y a. 235°T, 18.6 knots
    N b. 245°T, 20.0 knots
    N c. 325°T, 22.4 knots
    N d. 335°T, 23.6 knots

835: When taking stars, those bodies to the east and west will __________.

    Y a. change altitude rapidly
    N b. change altitude slowly
    N c. remain in an almost fixed position
    N d. appear to be moving in the plane of the horizon

885: The daily path of a celestial body that is parallel to the celestial equator is the __________.

    N a. altitude circle
    N b. vertical circle
    Y c. diurnal circle
    N d. hour circle

892: When a buoy is in position only during a certain period of the year, where may the dates when the buoy is in position be found?

    Y a. Light List
    N b. Notice to Mariners
    N c. On the chart
    N d. Coast Pilot

903: Eight points of a compass are equal to how many degrees?

    N a. 45
    Y b. 90
    N c. 180
    N d. 360

905: The Sun's center is coincident with the principal vertical circle when __________.

    Y a. in lower transit
    N b. the hour circle and prime vertical are coincident
    N c. the declination is zero degrees and the azimuth is exactly N 135°E
    N d. the declination is zero degrees and the azimuth is exactly N 135°W

958: You are preparing a weather report form. Twenty-five percent of the sky is covered with clouds, and the anemometer indicates that the apparent wind is from 062° relative at 13 knots. You are on course 238°T at 22 knots. How should you encode group Nddff? (D041NG )

    Y a. 20220
    N b. 20613
    N c. 30219
    N d. 32413

1010: What is a characteristic of a rhumb line?

    N a. It is the shortest distance between two points on the Earth.
    N b. It plots as a straight line on a Lambert conformal chart.
    Y c. It cuts each meridian at the same angle.
    N d. The course angle constantly changes to form the loxodromic curve.

1033: Deviation which is maximum on intercardinal compass headings may be removed by the __________.

    N a. Flinders bar
    N b. transverse magnets
    N c. fore-and-aft magnets
    Y d. soft iron spheres on the sides of the compass

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

1067: The two most effective generating forces of surface ocean currents are __________.

    N a. temperature and salinity differences in the water
    Y b. wind and density differences in the water
    N c. water depth and underwater topography
    N d. rotation of the Earth and continental interference

1106: The legend/symbol which designates an occluded front is represented by a __________.

    N a. red line
    Y b. purple line
    N c. blue line
    N d. dashed blue line

1110: 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. At the predicted time
    Y b. 30 minutes before the predicted time
    N c. One hour after the predicted time
    N d. 30 minutes before flood, one hour after an ebb

1135: A position on the Earth has a longitude of 74°10'E. Its celestial counterpart would have a __________.

    Y a. GHA of 285°50'
    N b. SHA of 74°10'
    N c. SHA of 285°50'
    N d. LHA of 74°10'E

1141: What is characteristic of an isophase light?

    N a. 4 sec. flash, 2 sec. eclipse, 3 sec. flash, 2 sec. eclipse
    N b. 2 sec. flash, 5 sec. eclipse
    Y c. 1 sec. flash, 1 sec. eclipse
    N d. 6 sec. flash, 3 sec. eclipse

1253: The horizontal angle between the magnetic meridian and the north-south line of the magnetic compass is __________.

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

1260: On 26 February 1983, at 1750 EST (ZD +5) what will be the predicted height of tide at New Haven (city dock), CT?

    N a. -.3 foot (-0.1 meter)
    Y b. -.6 foot (-0.2 meter)
    N c. 1.3 feet (0.4 meter)
    N d. 1.6 feet (0.5 meter)

1268: On a nautical chart, the inner ring of a compass rose indicates __________.

    N a. true directions
    N b. compass error
    N c. deviation
    Y d. magnetic directions

1304: The distance to the nearest vertex from any point on a great circle track cannot exceed __________.

    Y a. 5400 nautical miles
    N b. 5840 nautical miles
    N c. 6080 nautical miles
    N d. 10,800 nautical miles

1377: What is the velocity of the tidal current at the east end of Pollock Rip Channel at 1700 DST (ZD +4) on 23 July 1983?

    N a. 0.6 knot ebbing
    N b. 0.8 knot flooding
    Y c. 1.5 knots flooding
    N d. 1.9 knots flooding

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

1542: To find a magnetic course from a true course you must apply __________.

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

1589: You are enroute to Savannah, GA, from Recife, Brazil. There is a strong N'ly wind blowing. As you cross the axis of the Gulf Stream you would expect to encounter __________.

    N a. smoother seas and warmer water
    Y b. steeper waves, closer together
    N c. long swells
    N d. cirrus clouds

1635: An isotherm is __________.

    N a. a line on a weather map connecting equal points of both temperature and pressure
    N b. an instrument that measures the climatological effects of temperature
    N c. a line connecting points of equal barometric pressure on a weather map
    Y d. a line connecting points of equal temperature on a weather map

1890: A vessel heading SSE is on a course of __________.

    N a. 112.5°
    N b. 135.0°
    Y c. 157.5°
    N d. 180.0°

1916: The prime vertical is the reference point from which the angle of which type of observation is measured?

    N a. Sextant angle
    N b. Azimuth
    Y c. Amplitude
    N d. Local apparent noon

2019: At evening stars, the last stars that should be observed are those with an azimuth in what quadrant?

    N a. Southern
    Y b. Western
    N c. Northern
    N d. Eastern

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

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)

2192: Off Fire Island, NY, with winds from the southwest, the average wind-driven current flows in a direction of __________.

    N a. 256°
    N b. 170°
    Y c. 076°
    N d. 014°

2250: The most important information to be obtained from a barometer is the __________.

    N a. difference between the reading of the two pointers, which shows wind direction
    N b. last two figures of the reading of the pointer, such as .87, .76, or .92
    Y c. present reading of the pressure, combined with the changes in pressure observed in the recent past
    N d. weather indications printed on the dial (such as "cold, wet, etc.") under the pointer

2286: Which light signal indicates that you have permission to enter a lock on the Ohio River?

    N a. Steady red
    N b. Flashing amber
    N c. Steady green
    Y d. Flashing green

2322: You have completed the magnetic compass adjustments on magnetic east and magnetic south. The vessel is now steady on magnetic north but the compass reads 356°. Which action should be taken?

    N a. Use the fore-and-aft magnets and adjust the compass until it reads 358°.
    Y b. Use the athwartships magnets and adjust the compass until it reads 358°.
    N c. Use the fore-and-aft magnets and adjust the compass until it reads 000°.
    N d. Use the quadrantal spheres and adjust the compass until it reads 000°.

2348: Under the IALA cardinal system, a mark with a quick light showing 9 flashes every 15 seconds indicates that the safest water is on the __________.

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

2364: The immediate surroundings of what constellation contain the most first magnitude stars?

    N a. Libra
    N b. Cassiopeia
    N c. Pegasus
    Y d. Orion

2460: You are on course 344°T and take a relative bearing of a lighthouse of 270°. What is the true bearing to the lighthouse?

    N a. 016°
    N b. 074°
    N c. 090°
    Y d. 254°

2512: In the time diagram shown __________. (D005NG )

    Y a. you are in east longitude
    N b. your time is about 1000
    N c. your date is a day earlier than the date at Greenwich
    N d. you must be in the Northern Hemisphere for it to be accurate

2530: The distance between any two meridians measured along a parallel of latitude __________.

    N a. increases in north latitude and decreases in south latitude
    N b. decreases as DLO increases
    N c. increases with increased latitude
    Y d. decreases with increased latitude

2738: While navigating in fog off a coastline of steep cliffs, you hear the echo of the ship's fog horn 3 seconds after the signal was sounded. What is the distance to the shore?

    N a. 1100 yards
    N b. 872 yards
    Y c. 550 yards
    N d. 792 yards

2809: The diurnal variation of pressure is not visible in the middle latitudes in winter because __________.

    Y a. it is masked by the pressure changes of moving weather systems
    N b. the decreased gravitational effect from the sun causes the variation to fade
    N c. the decreased average temperature is less than the critical temperature
    N d. the increased Coriolis force disperses the pressure variation

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

3037: The letter H in illustration D006NG represents the __________.

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

3093: ECDIS must have the capability to preserve the record of the track for the previous __________.

    N a. 4 hours
    N b. 6 hours
    Y c. 12 hours
    N d. 24 hours