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.


15: What is the length of a nautical mile?


65: The LMT of LAN is 1210. Your longitude is 70°30'E. Which time would you use to enter the Nautical Almanac to determine the declination of the Sun at LAN?


264: Which of the four adjustable errors in the sextant is the principle cause of index error?


276: The region of high pressure extending around the Earth at about 35°N latitude is called the __________.

    N a. prevailing westerlies
    Y b. horse latitudes
    N c. troposphere
    N d. doldrums

315: Which statement about the time diagram shown DO08NG is TRUE?

    N a. You are in west longitude.
    N b. Your date is ahead of Greenwich.
    Y c. The meridian angle of the Sun is east.
    N d. The GHA of the Sun is less than 180°.

364: What causes the error of collimation with regards to the four adjustments to a sextant?

    Y a. Telescope not parallel to the frame
    N b. Personal error
    N c. The frame and index mirror not perpendicular
    N d. The frame and horizon glass not perpendicular

587: Your vessel has a draft of 34 feet. On 8 October 1983 you wish to pass over an obstruction near Jaffrey Point, NH, that has a charted depth of 31 feet. Allowing for a safety margin of 3 feet, what is the earliest time after 0900 DST (ZD +4) that this passage can be made?

    N a. 0920
    Y b. 1029
    N c. 1120
    N d. 1159

611: Information markers, when lighted, will display __________.

    N a. yellow lights
    N b. green lights
    Y c. white lights
    N d. red lights

622: The scale of a Mercator projection is 4 inches equals 1°LONG. What is the expansion in inches between the 60th and 61st parallels?

    Y a. 8.11 inches
    N b. 7.70 inches
    N c. 7.48 inches
    N d. 6.98 inches

660: What is the length of a nautical mile?

    N a. 1,850 meters
    N b. 5,280 feet
    N c. 1,760 yards
    Y d. 6,076 feet

670: A NAVAREA warning carries the following number; 1986/87 (11). Which statement is TRUE?

    N a. The warning was issued in 1986, the 87th sequentially numbered warning and broadcast 11 times.
    Y b. This is warning number 1986 issued in 1987, and it affects sub-region 11.
    N c. This warning is valid in 1986 and 1987 and is the eleventh two-year warning.
    N d. The subject of this warning first appeared in 1986; this warning is in 1987 and is the eleventh on this topic.

725: The First Point of Aries is the position of the Sun on the celestial sphere on or about __________.

    Y a. March 21
    N b. June 21
    N c. September 21
    N d. December 21

777: With respect to a reversing current, slack water occurs when there is __________.

    Y a. little or no horizontal motion of the water
    N b. little or no vertical motion of the water
    N c. a weak ebb or flood current
    N d. when winds cause water to back up in a river mouth

785: An amplitude of the Sun in high latitudes __________.

    N a. is most accurate before sunrise
    N b. is most accurate after sunset
    N c. should only be observed when the Sun's lower limb is above the horizon
    Y d. is most accurate when the Sun's center is observed on the visible horizon

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

851: You would expect to find channels marked with the IALA-A Buoyage System in __________.

    N a. the Philippines
    Y b. Australia
    N c. Republic of Korea
    N d. Chile

852: What is published by the U.S. Coast Guard?

    Y a. Light List
    N b. Nautical Charts
    N c. Tide Tables
    N d. U.S. Coast Pilot

876: A generally circular low pressure area is called a(n) __________.

    Y a. cyclone
    N b. anticyclone
    N c. cold front
    N d. occluded front

891: Under the IALA-A Buoyage System, a buoy indicating the preferred channel is to port would have __________.

    N a. an even number
    N b. an odd number
    N c. a pillar shape
    Y d. horizontal bands

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

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

993: When crossing the magnetic equator the __________.

    N a. Flinders bar should be inverted
    Y b. heeling magnet should be inverted
    N c. the quadrantal spheres should be rotated 180°
    N d. Flinders bar should be moved to the opposite side of the binnacle

1080: Information on northern right whales can be found in __________.

    Y a. the Coast Pilot
    N b. HO 229
    N c. the Nautical Almanac
    N d. Ship's Medicine Chest and Medical Aid at Sea

1194: In the Northern Hemisphere, an observer at point II in the weather system should experience a wind shift from the __________. (D014NG )

    Y a. southwest, clockwise to northwest
    N b. northeast, clockwise to west-southwest
    N c. northeast, counterclockwise to northwest
    N d. east, counterclockwise to south-southwest

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

1315: What is a lighted safe water mark fitted with to aid in its identification?

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

1384: Which type of cloud is indicated by number 9? (D039NG )

    N a. Cumulus
    Y b. Cumulonimbus
    N c. Altostratus
    N d. Stratocumulus

1444: Stratocumulus clouds are indicated by which number? (D039NG )

    N a. 1
    N b. 4
    Y c. 6
    N d. 7

1447: What will be the velocity of the tidal current 6 miles south of Shoal Point, NY, at 1850 DST (ZD +4) on 9 July 1983?

    N a. 0.2 knot ebb
    Y b. 0.2 knot flood
    N c. 1.2 knot ebb
    N d. 1.4 knot flood

1494: Cirrocumulus clouds are indicated by which number? (D039NG )

    N a. 7
    N b. 5
    Y c. 3
    N d. 1

1528: Cirrostratus clouds are indicated by which number? (D039NG )

    N a. 1
    Y b. 2
    N c. 8
    N d. 9

1560: Under the IALA-A and B Buoyage Systems, a buoy with alternating red and white vertical stripes indicates __________.

    Y a. that there is navigable water all around
    N b. an isolated danger exists
    N c. that the preferred channel is to port
    N d. that the preferred channel is to starboard

1565: Determine the approximate geographic visibility of an object, with a height above the water of 85 feet (25.9 meters), for an observer with a height of eye of 60 feet (18.3 meters).

    N a. 18.4 nm
    Y b. 19.9 nm
    N c. 20.8 nm
    N d. 21.5 nm

1601: Sextant B in illustration D043NG reads __________. (D043NG )

    N a. 30°51.0'
    Y b. 30°42.5'
    N c. 30°47.5'
    N d. 31°00.0'

1637: Which of the following is NOT a form of precipitation?

    N a. rain
    Y b. frost
    N c. sleet
    N d. snow

1671: Cirrus clouds are composed primarily of __________.

    Y a. ice crystals
    N b. water droplets
    N c. snow crystals
    N d. nitrogen

1675: You are entering port and have been instructed to anchor, as your berth is not yet available. You are on a SW'ly heading, preparing to drop anchor, when you observe the range lights as shown on your starboard beam. You should __________. (D047NG )

    N a. NOT drop the anchor until the lights are in line
    Y b. ensure your ship will NOT block the channel or obstruct the range while at anchor
    N c. drop the anchor immediately as the range lights mark an area free of obstructions
    N d. drop the anchor immediately as a change in the position of the range lights will always be an indication of dragging anchor

1749: If the current and wind are in opposite directions, the sea surface represents __________.

    N a. a greatly reduced wind speed
    Y b. a higher wind speed than what really exists
    N c. a lower wind speed than what really exists
    N d. more turbulent winds

1793: Which weather element cannot be measured accurately while on board a moving vessel?

    N a. relative humidity
    N b. temperature
    Y c. true wind speed
    N d. atmospheric pressure

1902: Under the numbering system used by NGA (NIMA), a four digit number is used for __________.

    N a. large scale charts of infrequently navigated areas such as the polar regions
    N b. charts of rivers or canal systems such as the Ohio River or Erie Canal
    Y c. non-navigational materials, such as a chart correction template or maneuvering board
    N d. foreign charts reproduced by NGA (NIMA)

1948: "Space motion" is the __________.

    N a. action causing precession of the equinoxes
    Y b. motion of a body in the solar system relative to the stars
    N c. motion of a celestial body in its orbit
    N d. irregularity in the motion of the Earth caused by other celestial bodies

2042: At morning stars, the last stars that should be observed are those with an azimuth in which quadrant?

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

2163: The letter C in illustration D006NG represents the __________.

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

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°.

2317: The Light List indicates that a light has a nominal range of 13 miles and is 36 feet high (11.0 meters). If the visibility is 7.0 miles and your height of eye is 25 feet (7.6 meters), at what approximate distance will you sight the light?

    Y a. 10.0 miles
    N b. 12.9 miles
    N c. 14.2 miles
    N d. 17.0 miles

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°.

2328: Universal time (UTI) is another name for __________.

    N a. sidereal time
    Y b. Greenwich mean time
    N c. ephemeris time
    N d. atomic time

2376: A large group of stars revolving around a center is known as a __________.

    N a. cluster
    N b. shower
    N c. constellation
    Y d. galaxy

2379: The winter solstice is the point where the Sun is at __________.

    N a. maximum declination north
    Y b. maximum declination south
    N c. 0° declination going to northerly declinations
    N d. 0° declination going to southerly declinations

2438: The radar control that reduces weak echoes out to a limited distance from the ship is the __________.

    Y a. sensitivity time control (sea-clutter control)
    N b. receiver gain control
    N c. brilliance control
    N d. fast time constant (differentiator)

2492: A star that suddenly becomes several magnitudes brighter and then gradually fades is a __________.

    N a. double star
    N b. variable star
    Y c. nova
    N d. nebula

2594: At McAlpine L & D, normal upper pool elevation is 420.0 feet (130.8 meters) MSL, equal to 12.0 feet (3.7 meters) on the upper gage. The vertical clearance at the Clark Memorial Highway bridge is 72.6 feet (22.1 meters) above normal pool. What is the clearance if the gage reads 10.6 feet (3.2 meters)?

    N a. 84.6 feet (25.8 meters)
    N b. 83.2 feet (25.4 meters)
    Y c. 74.0 feet (22.6 meters)
    N d. 62.0 feet (18.9 meters)

2640: In the celestial equator system of coordinates what is the equivalent to the meridians of the Earth system of coordinates?

    N a. Horizon
    Y b. Hour circles
    N c. Vertical circles
    N d. Parallel of declination

2668: You are approaching a drawbridge and have sounded the request-for-opening signal. The bridge has responded with five short blasts. What reply should you sound?

    N a. None; No reply is required
    Y b. Five short blasts
    N c. Two prolonged blasts
    N d. One prolonged, one short blast

2760: You are pushing a tow ahead, at high speed, near the right hand bank of a canal. The forces affecting your towboat and tow will tend to __________.

    N a. push both the head of the tow and the stern of the towboat away from the right hand bank
    Y b. push the head of the tow away from, and pull the stern of the towboat into, the right hand bank
    N c. pull both the head of the tow and the stern of the towboat into the right hand bank
    N d. pull the head of the tow into, and push the stern of the towboat away from, the right hand bank

2805: You are entering port and have been instructed to anchor, as your berth is not yet available. You are on a SW'ly heading, preparing to drop anchor, when you observe the range as shown on your starboard beam. You should __________. (D047NG )

    N a. drop the anchor immediately as the range lights mark an area free of obstructions
    N b. drop the anchor immediately as a change in the position of the range lights will be an indication of dragging anchor
    N c. NOT drop the anchor until the lights are in line
    Y d. ensure your ship will NOT block the channel or obstruct the range while at anchor

2858: While navigating in fog off a coastline of steep cliffs, you hear the echo of the ships fog horn 2 1/2 seconds after the signal was sounded. What is the distance to the shore?

    N a. 225 yards
    Y b. 460 yards
    N c. 750 yards
    N d. 910 yards

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

3095: ECDIS must have the capability to preserve the record of the track for the previous __________.

    N a. 6 hours
    Y b. 12 hours
    N c. 18 hours
    N d. 24 hours

3121: The short text messaging feature of the automatic identification system (AIS) allows for messages of up to___.

    N a. 64 characters
    N b. 96 characters
    Y c. 158 characters
    N d. 256 characters

3127: Which of the following statements is TRUE regarding automatic identification systems (AIS) ?

    N a. AIS cannot be used to make passing arrangements because the system is not capable of this type of ship-to-ship communications.
    N b. AIS cannot be used to make passing arrangements because the ship-to-ship text messaging feature is for emergency use only.
    Y c. AIS can be used to make passing arrangements via ship-to-ship text messaging but a vessel operator is not relieved from the requirement to sound whistle signals or make arrangements via bridge-to-bridge radiotelephone.
    N d. AIS can be used to make passing arrangements via ship-to-ship text massaging thus relieving a vessel operator from making such arrangements via bridge-to-bridge radiotelephone or signaling intent to pass via whistle signals.