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 __________.


50: The difference between the heights of low and high tide is the __________.


127: Mean low water is the average height of __________.


146: What change in the wind direction could be expected at position "D" if the low were moving northeasterly? (D049NG )

    Y a. Veering to the west
    N b. Backing to the north
    N c. Veering to the north
    N d. Backing to the east

158: Discounting slip, if your vessel is turning RPM for 10 knots and making good a speed of 10 knots, the current could be __________.

    N a. with you at 10 knots
    N b. against you at 10 knots
    Y c. slack
    N d. with you at 2 knots

248: What is the index error of sextant A in illustration D050NG? (D050NG )

    N a. 0° 10' off the arc
    N b. 0° 10' on the arc
    N c. 3° 00' off the arc
    Y d. 4° 20' off the arc

310: Which sextant shown has an index error of 3'30" off the arc? (D050NG )

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

404: An aneroid barometer is an instrument __________.

    N a. used to measure the speed of wind
    Y b. in which the pressure of the air is measured
    N c. that tells which direction a storm is coming from
    N d. used to measure the height of waves

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

436: A wind vane on a moving vessel shows __________.

    N a. dead reckoning wind direction
    N b. true wind direction
    Y c. apparent wind direction
    N d. estimated wind direction

581: The Captain of the Port has closed to navigation, and buoyed, a section of a harbor. These buoys would be painted __________.

    N a. red or green to conform with the other lateral aids
    N b. red and green horizontally-striped
    N c. solid yellow
    Y d. white with orange markings

582: Distance along a track line is measured on a Mercator chart by using the __________.

    Y a. latitude scale near the middle of the track line
    N b. longitude scale near the middle of the track line
    N c. latitude scale at the mid-latitude of the chart
    N d. latitude or longitude scale at the middle of the scale

600: The dangerous semicircle of a typhoon in the Southern Hemisphere is that area __________.

    N a. measured from due south clockwise 180°
    N b. measured from due south counterclockwise 180°
    Y c. to the left of the storm's track
    N d. ahead of the typhoon measured from the storm's track to 90° on each side

623: An indirect radar echo is caused by a reflection of the main lobe of the radar beam off the observer's vessel. Which of the following is NOT a characteristic of indirect echoes?

    N a. Their bearing is almost constant, even when the true bearing of the contact changes appreciably.
    Y b. They always appear on a bearing of 90°From the true bearing of the contact.
    N c. The indirect echoes usually appear in shadow sectors.
    N d. When plotted, their movements are usually abnormal.

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

635: A low HDOP (Horizontal Dilution of Precision) number such as 2 indicates a __________.

    N a. poor fix
    Y b. good fix
    N c. poor signal quality
    N d. good signal quality

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.

730: In the Northern Hemisphere, the largest waves or swells created by a typhoon or hurricane will be located __________.

    N a. in the southeast quadrant of the storm
    N b. directly behind the storm center
    Y c. forward and to the right of its course
    N d. behind and to the left of its course

768: The wind velocity is higher in the dangerous semicircle of a tropical cyclone because of the __________.

    Y a. wind circulation and forward motion of the storm
    N b. extension of the low pressure ridge
    N c. recurvature effect
    N d. direction of circulation and pressure gradient

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

804: A relative bearing is always measured from __________.

    N a. true north
    N b. magnetic north
    N c. the vessel's beam
    Y d. the vessel's head

818: Ocean swells originating from a typhoon can move ahead of it at speeds near __________.

    N a. 10 knots
    N b. 20 knots
    N c. 30 knots
    Y d. 50 knots

883: When changing from a compass course to a true course you should apply __________.

    N a. variation
    N b. deviation
    Y c. variation and deviation
    N d. a correction for the direction of current set

908: From LAT 07°12'N, LONG 80°00'W, to LAT 47°12'S, LONG 169°18'E, the initial great circle course angle is 137.25°. How would you name this course?

    N a. N 137.25°E
    N b. S 137.25°E
    Y c. N 137.25°W
    N d. S 137.25°W

952: What is TRUE concerning new editions of Light Lists?

    N a. Supplements to new editions are issued monthly by the U.S. Coast Guard.
    N b. New editions are published by the National Ocean Service.
    Y c. New editions are corrected through the date shown on the title page.
    N d. None of the above

980: 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
    Y b. become weak and variable
    N c. become reversing currents
    N d. exceed the predicted velocities

1150: You are on course 312°T. To check the speed of your vessel you should observe a celestial body on which bearing?

    Y a. 312°
    N b. 000°
    N c. 090°
    N d. 222°

1233: Deviation is the angle between the __________.

    N a. true meridian and the axis of the compass card
    N b. true meridian and the magnetic meridian
    Y c. magnetic meridian and the axis of the compass card
    N d. axis of the compass card and the degaussing meridian

1403: Which statement about the gyrocompass is FALSE?

    Y a. Its accuracy remains the same at all latitudes.
    N b. It seeks the true meridian.
    N c. It can be used near the Earth's magnetic poles.
    N d. If an error exists, it is the same on all headings.

1410: A white buoy marked with an orange rectangle indicates __________.

    N a. a fish net area
    Y b. general information
    N c. an anchorage
    N d. mid-channel

1522: The pressure-sensitive element of an aneroid barometer is called a __________.

    N a. pressure bellows
    Y b. sylphon cell
    N c. column of mercury
    N d. constant pressure capsule

1530: In shallow water, waves that are too steep to be stable, causing the crests to move forward faster than the rest of the wave, are called __________.

    N a. rollers
    Y b. breakers
    N c. white caps
    N d. surfers

1535: When observing a rapid rise in barometric pressure, you may expect __________.

    N a. clear weather with no wind, but the possibility of rain or snow within 24 hours
    N b. deteriorating weather with rain or snow
    N c. heavy rain or severe thundershowers
    Y d. clearing weather, possibly accompanied by high winds

1671: Cirrus clouds are composed primarily of __________.

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

1703: In the Northern Hemisphere, when the wind at your location is northerly, the low pressure center causing the wind is located to your __________.

    N a. NNW
    N b. WSW
    Y c. ESE
    N d. SSW

1768: A flashing red light displayed at a single lock means that the lock __________.

    N a. is ready to use but vessels must stand clear
    N b. is ready to use and vessels may approach
    Y c. cannot be made ready immediately and vessels shall stand clear
    N d. cannot be made ready immediately but vessels may approach

1801: A phenomenon where the atmospheric pressure is higher than that of other surrounding regions is called __________.

    N a. the "trade winds"
    Y b. an anticyclone
    N c. a low front or an occluded front
    N d. the "doldrums"

1924: The point on the celestial sphere that is directly below an observer is the __________.

    N a. pole
    Y b. nadir
    N c. node
    N d. zenith

1949: "Revolution" is the __________.

    N a. wobbling of the Earth about its axis
    N b. motion of bodies in the solar system relative to the stars
    Y c. motion of a celestial body in its orbit
    N d. spinning of a celestial body about its axis

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

2050: The point where the vertical rise or fall of tide has stopped is referred to as __________.

    N a. slack water
    N b. the rip tide
    Y c. the stand of the tide
    N d. the reverse of the tide

2078: If a towboat requires a double lockage it shall give which sound signal at a distance of not more than one mile from the lock?

    N a. One short blast followed by two long blasts
    N b. One long blast followed by one short blast
    N c. Two long blasts followed by one short blast
    Y d. One long blast followed by two short blasts

2175: Diagram Number D037NG represents a movable dam. If there is high water and the wickets are down so that there is an unobstructed navigable pass through the dam, which light(s) will be shown at D if the lock walls and piers are not awash?

    N a. One amber light
    Y b. One red light
    N c. Two red lights
    N d. Three red lights

2374: The largest of the navigational planets is __________.

    N a. Mars
    N b. Venus
    Y c. Jupiter
    N d. Saturn

2444: What is the equivalent of 0°48' in time units?

    N a. 2 min. 12 sec.
    N b. 2 min. 42 sec.
    N c. 3 min. 02 sec.
    Y d. 3 min. 12 sec.

2548: On the Mississippi River, gage zero is the gage reading measured from the __________.

    Y a. National Geodetic Vertical Datum
    N b. low water reference plane
    N c. the lowest recorded river depth
    N d. the highest recorded river depth

2588: You are approaching an open drawbridge and sound the proper signal. You receive no acknowledgment from the bridge. Which action should you take?

    Y a. Approach with caution and proceed through the open draw.
    N b. Approach under full control to a position no closer than 400 yards from the bridge and await a signal from the bridge.
    N c. Hold in the channel as a vessel is closing the bridge from the other direction.
    N d. Resound the opening signal and do not pass through the bridge until signals have been exchanged.

2589: Under the IALA cardinal system, a mark with a quick white light showing 6 flashes followed by one long flash indicates that the safest water is on the __________.

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

2644: The sidereal day begins __________.

    N a. when the sun is over the first point of Aries
    N b. when the first point of Aries is over 180° longitude
    Y c. when the first point of Aries is over the upper branch of the reference meridian
    N d. at 0000 on 1 January (Sidereal Date)

2649: The letter C in illustration D006NG represents the __________. (D006NG )

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

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

2694: What is the equivalent of 10°48' in time units?

    N a. 2 min. 39 sec.
    N b. 20 min. 12 sec.
    Y c. 43 min. 12 sec.
    N d. 50 min. 12 sec.

2764: You are in a channel inbound from sea. A daymark used to mark a channel junction when the preferred channel is to port will have the shape indicated by what letter in illustration D045NG?

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

2766: In low latitudes, the high(s) of the diurnal variation of pressure occur(s) at __________.

    N a. noon
    N b. noon and midnight
    Y c. 1000 and 2200
    N d. 1600

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

2904: Your radar displays your ship off center. As you proceed on your course, your ship's marker moves on the PPI scope while echoes from land masses remain stationary. What is this display called?

    N a. Off center
    Y b. True motion
    N c. Stabilized
    N d. Head up

2932: If the main channel under a bridge is marked with lights of the lateral system the adjacent bridge piers should be marked with __________.

    N a. occulting white lights
    Y b. fixed yellow lights
    N c. fixed white lights
    N d. flashing yellow lights

2945: A position that is obtained by applying estimated current and wind to your vessel's course and speed is a(n) __________.

    Y a. estimated position
    N b. dead reckoning position
    N c. fix
    N d. None of the above

2990: In which source could you find the vertical clearance of a bridge on the Ohio River?

    N a. Notice to Mariners
    Y b. Light List of the Mississippi River System
    N c. Great Lakes Pilot
    N d. Coast Pilot of the Gulf of Mexico

3094: ECDIS must have the capability to preserve the record of the track for the previous __________.

    Y a. 12 hours
    N b. 24 hours
    N c. 48 hours
    N d. 72 hours