USCG Navigation Problems: 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.


80: The Helena Gage reads 9.4 feet. The high point on your towboat is 46 feet above water. What is the vertical clearance when you pass under the Helena Highway Bridge?


94: You have orders to drop off the empties at the fleeting area in Cairo and add five loaded barges to your tow. If you are turning for 8 mph and estimate the current at 0.5 mph, what is your ETA at Cairo?


122: From Baton Rouge to Cairo, what is the maintained minimum channel depth during low water?


179: In order to check your compasses, you sight North Dumpling Island Light in line with Latimer Reef Light bearing 077°pgc. The helmsman was steering 307°pgc and 320° per standard magnetic compass at the time. Which statement is TRUE?

    N a. The gyro error by observation is 2°E.
    N b. The deviation based on the observation is 15°W.
    Y c. The magnetic compass error is 14°W.
    N d. The true line of the range is 079°.

185: At 1950, your position is LAT 37°12.3'N, LONG 75°38.6'W. The set and drift from 1930 to 1950 were __________.

    Y a. 150°T at 1.6 knot
    N b. 150°T at 0.6 knots
    N c. 330°T at 0.6 knot
    N d. 330°T at 1.6 knots

365: You sighted Trestle "A" in line at 0707 and are steering 108°T. At 0731, Cape Henry Light bears 136°T; Cape Charles Light bears 032.5°T; and Thimble Shoal Tunnel South Light bears 282°T. What was the speed made good between 0707 and 0731?

    N a. 9.4 knots
    N b. 9.2 knots
    Y c. 8.8 knots
    N d. 8.3 knots

370: At 0812, you are on course 132°T. The standard magnetic compass reads 135°. What should you conclude?

    N a. The deviation table is correct for that heading.
    N b. You should adjust the magnetic compass.
    N c. The deviation is increasing as you go south.
    Y d. Your compass may be influenced by a local magnetic disturbance.

395: A vessel at LAT 45°36.0'N, LONG 11°36.0'W, heads for a destination at LAT 24°16.0'N, LONG 73°52.0'W. Determine the true course and distance by Mercator sailing.

    Y a. 247°T, 3299.3 miles
    N b. 247°T, 3951.6 miles
    N c. 251°T, 3298.5 miles
    N d. 251°T, 3951.6 miles

477: The great circle distance from LAT 08°50.0'N, LONG 80°21.0'W to LAT 12°36.0'N, LONG 128°16.0'E is 8664 miles, and the initial course is 306.6°T. Determine the latitude of the vertex.

    Y a. 37°30.2'N
    N b. 37°39.6'N
    N c. 37°48.2'N
    N d. 37°53.6'N

506: At 0112, what is the approximate depth under the keel?

    N a. 57 feet (17.3 meters)
    N b. 51 feet (15.5 meters)
    N c. 47 feet (14.2 meters)
    Y d. 38 feet (11.5 meters)

576: What is indicated by the dashed magenta line crossing York Spit Channel between buoys "20" and "22"?

    N a. You are crossing the demarcation line between the COLREGS and the Inland Rules.
    N b. The line indicates a submarine cable, and you should not anchor in the area.
    Y c. The line marks the limits of a regulated area.
    N d. It marks the range between Ft. Wool Light and Cape Charles Harbor Range, Rear Light.

576: What is indicated by the dashed magenta line crossing York Spit Channel between buoys "20" and "22"?

    N a. You are crossing the demarcation line between the COLREGS and the Inland Rules.
    N b. The line indicates a submarine cable, and you should not anchor in the area.
    Y c. The line marks the limits of a regulated area.
    N d. It marks the range between Ft. Wool Light and Cape Charles Harbor Range, Rear Light.

630: You are on a voyage from Corpus Christi, TX, to Fort de France, Martinique. The distance from pilot to pilot is 2190 miles (2521 statute miles). The speed of advance is 15.0 knots. You estimate a layover in Charlotte Amalie, Virgin Islands, of 16.0 hours. If you take departure at 0654 (ZD +6), 27 November, what is your ETA (ZD +4) at Fort de France?

    N a. 2054, 3 December
    N b. 2254, 3 December
    Y c. 0254, 4 December
    N d. 2054, 4 December

732: On 3 January , your 1759 zone time DR position is LONG 60°53.2'W. At that time you observe Polaris with a sextant altitude (hs) of 22°55.8'. The chronometer time of the sight is 09h 57m 10s, and the chronometer error is 02m 26s slow. The index error is 2.9' off the arc, and the height of eye is 52.5 feet. What is your latitude by Polaris?

    N a. 21°35.2'N
    N b. 21°52.5'N
    Y c. 22°03.6'N
    N d. 22°22.6'N

733: On 12 March , your 1846 zone time DR position is LONG 129°16.5'W. At that time you observe Polaris with a sextant altitude (hs) of 28°01.5'. The chronometer time of the sight is 03h 44m 10s, and the chronometer error is 01m 55s slow. The index error is 2.2' off the arc, and the height of eye is 59.8 feet (18.2 m). What is your latitude by Polaris?

    Y a. 27°33.7'N
    N b. 27°40.9'N
    N c. 27°54.4'N
    N d. 28°06.9'N

737: On 29 July , your 1930 zone time DR position is LONG 164°26.0'E. At that time you observe Polaris with a sextant altitude (hs) of 23°46.8'. The chronometer time of the sight is 08h 32m 18s, and the chronometer error is 02m 26s fast. The index error is 2.7' on the arc, and the height of eye is 56.0 feet. What is your latitude by Polaris?

    N a. 24°01.9'N
    Y b. 24°19.5'N
    N c. 24°31.7'N
    N d. 25°19.6'N

807: On 12 February your 0542 zone time (ZT) fix gives you a position of LAT 26°42.0'N, LONG 60°18.0'W. Your vessel is on course 300°T, and your speed is 9.8 knots. Local apparent noon (LAN) occurs at 1220 ZT at which time a meridian altitude of the Sun's lower limb is observed. The observed altitude (Ho) for this sight is 49°10.0'. What is the calculated latitude at LAN?

    N a. 27°13.5'N
    Y b. 27°16.3'N
    N c. 27°17.6'N
    N d. 27°19.2'N

820: On 15 March , in DR position LAT 21°42.0'N, LONG 55°26.0'W, you take an ex-meridian observation of the Sun's lower limb. The chronometer time of the sight is 04h 02m 40s, and the chronometer error is 02m 24s fast. The sextant altitude (hs) is 66°15.6'. The index error is 2.8' on the arc, and your height of eye is 56 feet. What is the latitude at meridian transit?

    N a. 21°12.0'N
    N b. 21°18.0'N
    N c. 21°24.4'N
    Y d. 21°32.0'N

1103: On 25 August , your 0300 zone time DR position is LAT 21°28.0'N, LONG 167°48.0'E. You are on course 248°T at a speed of 12 knots. You observed 3 celestial bodies. Determine the latitude and longitude of your 0600 running fix. NP-0032

    N a. LAT 20°52.4'N, LONG 167°32.1'E
    Y b. LAT 20°57.1'N, LONG 167°01.0'E
    N c. LAT 20°59.5'N, LONG 166°54.8'E
    N d. LAT 21°06.0'N, LONG 167°10.9'E

1658: On 23 August , in DR position LAT 24°07.0'N, LONG 136°16.0'E, you observe an amplitude of the Sun. The Sun's center is on the visible horizon and bears 074.5°psc. The chronometer reads 08h 56m 19s and is 02m 34s fast. Variation in the area is 2°W. What is the deviation of the magnetic compass?

    N a. 2.5°E
    N b. 2.8°W
    Y c. 4.5°E
    N d. 4.8°W

1746: The Crooked River empties into which river?

    Y a. Missouri
    N b. Mississippi
    N c. Tennessee
    N d. Ohio

1900: On 22 May , your 0437 DR position is LAT 25°18.5'N, LONG 51°18.0'W. You observed an unidentified star bearing 233°T at an observed altitude (Ho) of 29°42.3'. The chronometer reads 07h 40m 40s, and is 03m 24s fast. What star did you observe?

    N a. Markab
    N b. Diphda
    Y c. Sabik
    N d. Hamal

1963: Which of the following statements are TRUE?

    N a. Oil well structures are listed in the Light List.
    N b. All aids to navigation with lights have lateral significance.
    Y c. On the Western Rivers, crossing marks may exhibit white lights.
    N d. All of the above.

2060: The highest point on your towboat is 67 feet above the water, and the Helena Gage reads +22.3 feet. What is the vertical clearance when you pass under the A-span of the Helena Highway Bridge?

    Y a. 30.1 feet
    N b. 49.8 feet
    N c. 52.4 feet
    N d. 74.7 feet

2165: On 25 February , at 0622 ZT, you observe the upper limb of the Moon with a sextant altitude of 59°58.6'. Your DR position is LAT 30°28.3'S, LONG 102°39.3 E. The chronometer reading at the time of the sight is 11h 21m 18s and the chronometer is 48s slow. The height of eye is 59 feet and the index error is 2.5' on the arc. What are the azimuth (Zn) and intercept (a) of this sight using the assumed position?

    Y a. Zn 305.4°, a 4.2°T
    N b. Zn 234.6°, a 4.2° A
    N c. Zn 305.4°, a 1.5°T
    N d. Zn 305.4°, a 9.2°T

2322: At 1032 on 24 June, you pass Carolina Landing Light (mile 508.8 AHP). What has been the average current since 2350, 23 June, if you have been making turns for 9.0 mph?

    Y a. 0.5 mph
    N b. 1.5 mph
    N c. 5.7 mph
    N d. 8.5 mph

2534: Your company wants to know at what time you will be arriving at the fleeting area at Sycamore Chute Light (mile 740.3 AHP) in Memphis, TN You are making turns for 9.0 mph and you estimate the average current at 2.2 mph. Figuring the distance and time from Hole in the Wall Lt. (mile 373.4 AHP), what is your ETA at Sycamore Chute Lt.?

    N a. 0557, April 19th
    N b. 1045, April 19th
    Y c. 1242, April 19th
    N d. 1733, April 19th

2673: At 2221 your course is 222°pgc at a speed of 11.2 knots, when radar detects a buoy bearing 355° relative, at a range of 5.8 miles. The gyro error is 2°E. If you change course at 2226, what course should you steer to leave the buoy 1.0 mile abeam to port?

    N a. 206°pgc
    N b. 210°pgc
    Y c. 228°pgc
    N d. 231°pgc

2683: You are underway on a course of 135°pgc at 15 knots, and you sight a lighthouse dead ahead at a range of 12.5 miles at 1145. What course would you steer to leave the lighthouse 3.0 miles off your port beam?

    N a. 117°pgc
    N b. 121°pgc
    Y c. 149°pgc
    N d. 154°pgc

3089: If the pitch of the propeller is 22.4 feet, and the revolutions per day are 103,690, calculate the day's run allowing 9% positive slip.

    N a. 321.7 miles
    Y b. 347.6 miles
    N c. 382.0 miles
    N d. 416.4 miles

3651: The true course between two points is 337°. Your gyrocompass has an error of 3°E and you make an allowance of 5° leeway for a west wind. Which gyro course should be steered to make the true course good?

    Y a. 329°pgc
    N b. 335°pgc
    N c. 339°pgc
    N d. 345°pgc

4010: You swung ship and compared the magnetic compass against the gyro compass to find deviation. Gyro error is 2°E. The variation is 8°W. Find the deviation on a magnetic compass heading of 104°.
HEADING HEADING HEADING
PSC PGC PSC PGC PSC PGC
358.5° - 350° 122.5° - 110° 239.5° - 230°
030.5° - 020° 152.0° - 140° 269.0° - 260°
061.5° - 050° 181.0° - 170° 298.0° - 290°
092.0° - 080° 210.0° - 200° 327.5° - 320°

    N a. 1.8°E
    N b. 2.6°E
    Y c. 2.2°W
    N d. 2.7°W

10707: At 0726 you depart Lake Montauk with light 1 close aboard and set course 065° per standard magnetic compass at 6.7 knots. At 0912 your GPS position is LAT 41°12.8'N, LONG 71°48.2'W. What is the current?

    N a. 151°T at 1.0 knot
    N b. 164°T at 0.7 knot
    Y c. 287°T at 2.0 knots
    N d. 321°T at 0.8 knot

11006: At what time will the first maximum flood occur 1 mile east of Old Field Point on 29 April 1983? (You are keeping daylight saving time ZD +4).

    N a. 0957
    N b. 1059
    Y c. 1328
    N d. 1423

13106: At 1048 you are in the entrance to Great Salt Pond on Block Island with buoy "5" close aboard. What is your ETA at the west gap of Point Judith Harbor of Refuge if you make good 11.3 knots?

    Y a. 1144
    N b. 1154
    N c. 1159
    N d. 1205

15018: What course per standard magnetic compass (psc) is the same as 247°pgc?

    N a. 240°psc
    N b. 246°psc
    Y c. 257°psc
    N d. 260°psc

15156: Your 1600 position is LAT 37°22.5'N, LONG 75°32.3'W. The depth of water is about __________.

    N a. 38 feet (11.5 meters)
    N b. 45 feet (13.6 meters)
    Y c. 52 feet (15.8 meters)
    N d. 59 feet (17.3 meters)

15206: At 1730, your position is LAT 37°13.9'N, LONG 76°26.4'W. You are steering course 088° per standard magnetic compass (psc) at an engine speed of 8.0 knots. What is your distance off Tue Marshes Light at 1730?

    Y a. 2.6 miles
    N b. 2.8 miles
    N c. 3.0 miles
    N d. 3.2 miles

15357: If the visibility is 10 miles, what is the earliest time you can expect to see New Haven Light?

    N a. The light is visible at 0452.
    N b. 0458
    N c. 0510
    Y d. You will not sight the light.

15460: At 0845, you are approaching the entrances to Thimble Shoal Channel. What channel must you use?

    Y a. The South Auxiliary Channel since your draft is less than 25 feet (7.6 meters), and you are not a passenger vessel.
    N b. The South Auxiliary Channel or Thimble Shoal Channel, but you must remain on the right hand side of the main channel.
    N c. The North Auxiliary Channel since you are going to turn to a northerly heading near buoy "12".
    N d. You are not permitted to use any of the channels, but must remain outside the buoyed channel line.

15770: At 0930, your position is LAT 41°16.5'N, LONG 71°41.4'W, and you are turning for 7 knots. Allowing 3° leeway for northerly winds and estimating the current as 035° at 0.3 knot, what is the course to steer (pgc) to point "B"?

    N a. 084°pgc
    Y b. 086°pgc
    N c. 091°pgc
    N d. 094°pgc

15913: At 0830, you wish to get the latest weather forecasts for the Falkner Island area. On what frequency would you set your FM radio for this information?

    N a. 2181 kHz
    N b. 156.65 Mhz
    N c. 156.80 Mhz
    Y d. 162.40 Mhz

16017: What is the approximate distance to New Bedford, MA, from your 0530 DR position, if your 0352 position was 7 miles from Bridgeport, CT?

    N a. 77 miles
    N b. 91 miles
    Y c. 104 miles
    N d. 115 miles

16142: At 1949 Little Gull Island Light bears 270°T and is 1.7 miles off. From this position, you change course to 118°T and increase engine speed to 18 knots. If you make good your course and speed, at what time should Shagwong Reef Lighted Bell Buoy "7SR" bear 180°T?

    Y a. 2016
    N b. 2019
    N c. 2022
    N d. 2025

16308: At 0530, your position is LAT 41°13.6'N, LONG 72°08.5'W. What is the color of New London Harbor Light?

    Y a. Red
    N b. White
    N c. Green
    N d. Alternating white and green

16310: At 0730, your position is LAT 41°10.5'N, LONG 72°32.2'W. From this position you steer course 286°psc with an engine speed of 9.0 knots. What is the approximate depth of water under your keel?

    Y a. 52 feet (15.8 meters)
    N b. 57 feet (17.3 meters)
    N c. 62 feet (18.8 meters)
    N d. 67 feet (20.3 meters)

16319: As you enter the New Haven Outer Channel, you sight the outer range markers in line directly ahead. Your heading at this time is 347°psc. What is your compass deviation by observation?

    Y a. 0.5°East
    N b. 3.0°East
    N c. 3.5°West
    N d. 4.5°East

16469: As you pass between trestle "B" and trestle "C" of the Chesapeake Bay Bridge - Tunnel, you sight along the trestle "C" when it is in line. The trestle bears 057° per standard magnetic compass while the vessel is heading 320°T. From this you know the __________.

    Y a. vessel should be swung to check the deviation table
    N b. compass error is 12°W
    N c. deviation table is correct for that bearing
    N d. deviation is 10°W

16516: At 0815, visibility is excellent and you can see Montauk
Point. Montauk Point is __________.

    N a. low and rocky with scattered small pine trees
    N b. a low lying wetland
    N c. a flat wooded plain
    Y d. a high sandy bluff

16743: At 0040 you are south of Lewis Point when you receive word that the distress is terminated. You alter course to head for The Race. At 0052 you take the following relative bearings because the starboard gyro repeater is inoperative. Your heading at each bearing was 285°pgc. What is your 0052 position?

Race Rock Light 002°
Watch Hill Light 034°
Block Island North Light 122°

    N a. LAT 41°08.8'N, LONG 71°41.4'W
    N b. LAT 41°09.0'N, LONG 71°42.3'W
    N c. LAT 41°09.0'N, LONG 71°41.1'W
    Y d. LAT 41°09.1'N, LONG 71°41.7'W

16846: Your vessel's heading is 330°pgc and 345°psc with a 2°E gyro error. What is the deviation on this heading?

    N a. 0°
    Y b. 3°W
    N c. 4°E
    N d. 7°W