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.
40: The predicted time that the flood begins at the entrance to Delaware Bay is 1526. You are anchored off Chestnut St. in Philadelphia. If you get underway bound for sea at 1600 and turn for 8 knots, at what point will you lose the ebb current?
N a. Billingsport N b. Marcus Hook Y c. Mile 63 N d. Mile 52 248: 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 333: Loran-C stations transmit groups of pulses at specific times. The time interval between transmissions from the master station is the __________.
N a. coding delay Y b. group repetition interval N c. pulse interval N d. phase code 367: What will be the time after 0800 EST (ZD +5) that the height of the tide at South Freeport, ME, will be 6.0 feet (1.8 meters) on 7 November 1983?
N a. 0936 N b. 0942 Y c. 0951 N d. 1001 425: 90° - Ho = __________.
N a. sextant altitude N b. co-latitude N c. LHA Y d. zenith distance 533: You are using a radar in which your own ship is shown at the center, and the heading flash always points to 0°. If bearings are measured in relation to the flash, what type of bearings are produced?
Y a. Relative N b. True N c. Compass N d. Magnetic 536: You are enroute from Puerto Rico to New York. A hurricane makes up and is approaching. If the wind veers steadily, this indicates that your vessel is __________.
Y a. in the dangerous semicircle N b. in the navigable semicircle N c. directly in the path of the storm N d. in the storm center 626: What indicates the arrival of a hurricane within 24 to 36 hours?
N a. The normal swell becoming lower and from a steady direction N b. Long bands of nimbostratus clouds radiating from a point over the horizon N c. The barometer drops 2 millibars between 1000 and 1600 Y d. Unusually good weather with above average pressures followed by a slow fall of 4 millibars in six hours 630: What kind of weather would you expect to accompany the passage of a tropical wave?
Y a. Heavy rain and cloudiness N b. Good weather N c. A tropical storm N d. Dense fog 652: What agency of the U.S. Government issues charts of U.S. waters and Coast Pilots?
Y a. National Ocean Service N b. National Imagery and Mapping Agency N c. U.S. Coast Guard N d. U.S. Naval Observatory 678: On 25 December 1981 you observe the Sun's lower limb. The sextant altitude (hs) is 4°06.9'. The height of eye is 47 feet and the index error is 1.6' on the arc. The temperature is 19°F. and the barometer reads 1030.8 millibars. What is the observed altitude (Ho)?
N a. 3°57.4' Y b. 4°01.9' N c. 4°02.5' N d. 4°03.4' 687: The drift and set of tidal, river, and ocean currents refer to the __________.
N a. position and area of the current Y b. speed and direction toward which the current flows N c. type and characteristic of the current's flow N d. None of the above 719: You are on course 209°T. In order to check the longitude of your vessel, you should observe a celestial body on which bearing?
N a. 209° Y b. 270° N c. 299° N d. 000° 773: What is the basic principle of the magnetic compass?
Y a. Magnetic materials of the same polarity repel each other and those of opposite polarity attract. N b. The Earth's magnetic lines of force are parallel to the surface of the Earth. N c. Magnetic meridians connect points of equal magnetic variation. N d. The compass needle(s) will, when properly compensated, lie parallel to the isogonic lines of the Earth. 779: Which sextant shown has an index error of 0'20" on the arc? (D050NG )
N a. A N b. B Y c. C N d. D 1169: The symbols shown are used on radio facsimile weather charts. The symbol indicated at letter "O" represents __________. (D042NG )
Y a. sandstorms N b. thunderstorms N c. snow N d. rain showers 1202: As shown in the illustration, which wind speeds are reported at position A? (D049NG )
N a. 10 knots Y b. 15 knots N c. 20 knots N d. 25 knots 1243: Magnetic heading differs from compass heading by __________.
N a. compass error N b. true heading N c. variation Y d. deviation 1257: What will be the velocity of the tidal current 1.0 mile southwest of Lewis Pt., RI, at 1501 EST (ZD +5) on 4 April 1983?
Y a. 0.7 knot N b. 1.4 knots N c. 1.6 knots N d. 1.9 knots 1291: The period of a lighted aid to navigation refers to the __________.
N a. date of construction or establishment N b. length of time between flashes of the light N c. time required for the longest flash of each cycle Y d. time required for the light to complete each cycle 1306: What type of clouds are associated with a cold front?
N a. Altostratus and fracto-cumulus N b. Altostratus and cirrus N c. Cirrus and cirrostratus Y d. Cumulus and cumulonimbus 1316: When a warm air mass overtakes a cold air mass, the contact surface is called a __________.
N a. line squall N b. water spout N c. cold front Y d. warm front 1367: You want to transit Hell Gate, NY 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 0.3 knot?
N a. 0939 to 0957 Y b. 0943 to 0953 N c. 0844 to 0852 N d. 0348 to 0356 1380: Which type of weather could you expect soon after seeing "hook" or "comma" shaped cirrus clouds?
Y a. Rain with the approach of a warm front N b. Clearing with the approach of a cold front N c. Continuing fog and rain N d. The formation of a tropical depression 1412: The distance between the surface of the water and the tidal datum is the __________.
N a. actual water depth N b. range of tide N c. charted depth Y d. height of tide 1454: Atmospheric pressure may be measured with a(n) __________.
N a. barograph N b. aneroid barometer N c. mercurial barometer Y d. All of the above 1486: Which condition would most likely result in fog?
Y a. Warm moist air blowing over cold water N b. Airborne dust particles N c. Warm moist air blowing over warm water N d. Dew point falling below the air temperature 1561: You are sailing south on the Intracoastal Waterway (ICW) when you sight a red nun buoy with a yellow square painted on it. Which statement is TRUE?
N a. The buoy is off station and should be ignored as a navigational mark. N b. The waterway in that area has shoaled and the available depth of water is less than the project depth. N c. ICW traffic should not proceed beyond the buoy unless the crossing waterway is clear of all traffic. Y d. You should leave the buoy to port. 1637: Which of the following is NOT a form of precipitation?
N a. rain Y b. frost N c. sleet N d. snow 1661: Advection fog may be formed by warm moist air passing over a __________.
N a. warmer sea surface Y b. cooler sea surface N c. dry coastal plain N d. polar land mass 1680: A weather front exists when __________.
N a. air masses of the same temperature meet Y b. air masses of different temperatures meet N c. many clouds create a differential in air density N d. two lows are separated by a ridge of higher pressure 1683: As it approaches, a typical warm front will bring __________.
Y a. rising temperatures and falling barometric pressure N b. falling temperature and pressure N c. falling temperatures and rising pressure N d. rising barometric pressure and temperatures 1707: "Surface circulation" is another term for __________.
N a. cyclones N b. air in motion at all levels of the atmosphere Y c. wind in the lower troposphere N d. ocean currents 1780: While in port, you can follow the approach of a dangerous cyclonic storm by inspecting __________.
N a. the Coast Pilot or Sailing Directions N b. the National Weather Service Observing Handbook No.1, Marine Surface Observations Y c. a newspaper N d. the sky overhead 1860: A vessel heading WSW is on a course of __________.
N a. 202.5° N b. 225.0° Y c. 247.5° N d. 271.0° 1874: Lighted white and orange buoys must show which color light?
N a. Orange N b. Red N c. Alternating yellow and white Y d. White 1932: The zenith is the point on the celestial sphere that is __________.
N a. 90° away from the poles Y b. directly over the observer N c. on the eastern horizon N d. over Greenwich 1955: The letter A in illustration D006NG represents the __________.
N a. geoidal horizon Y b. sensible horizon N c. celestial horizon N d. visible horizon 1979: The principal vertical circle is that great circle on the celestial sphere that passes through the __________.
N a. zenith and the celestial body Y b. zenith and the north and south poles N c. poles and Greenwich N d. zenith and is parallel to the horizon 2014: Which stock number indicates an NGA (NIMA) chart designed for navigation outside of outlying reefs and shoals?
N a. 19BCO19243 Y b. WOPGN530 N c. LCORR5873 N d. 14XCO14902 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 2102: The subregions of the United States Gulf and East Coasts are numbered 11, 12 and 13 within the chart numbering system. Which chart number indicates a chart for either the Gulf or East Coast?
N a. 21214 Y b. 11314 N c. 14313 N d. 14114 2110: You are underway in a vessel with a draft of 6.0 feet. You are in an area where the charted depth of the water is 4 fathoms. You would expect the depth of water beneath your keel to be approximately __________.
N a. 12 feet Y b. 18 feet N c. 24 feet N d. 30 feet 2132: What is the definition of height of tide?
N a. The vertical difference between the heights of low and high water N b. The vertical difference between a datum plane and the ocean bottom Y c. The vertical distance from the tidal datum to the level of the water at any time N d. The vertical distance from the surface of the water to the ocean floor 2168: By convention, the north pole of a magnet is painted __________.
Y a. red N b. blue N c. white N d. black 2229: A vessel is heading magnetic north and its magnetic compass indicates a heading of 003°. What action should be taken to remove this error during compass adjustment?
Y a. If the red ends are to port the athwartships magnets should be raised. N b. If the blue ends are to port the athwartships magnets should be raised. N c. If the red ends are forward the fore-and-aft magnets should be lowered. N d. If the blue ends are forward the fore-and-aft magnets should be raised. 2276: A vessel is heading magnetic east and its magnetic compass indicates a heading of 086°. Which action should be taken to remove this error during compass adjustment?
Y a. If the blue ends of the magnets are aft, and the fore-and-aft tray is at the top, you should add some magnets. N b. If the blue ends of the magnets are aft you should lower the fore-and-aft tray. N c. If the blue ends of the magnets are aft, and the fore-and-aft tray is at the top, you should reverse the magnets. N d. If the blue ends of the magnets are forward, and the fore-and-aft tray is at the bottom, you should add some magnets. 2299: What condition exists at apogee?
N a. The Earth is closest to the Sun. N b. The Moon is farthest from the Sun. Y c. The Earth is farthest from the Moon. N d. The Moon is between the Earth and the Sun. 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 2363: As shown, the position labeled C was plotted because __________. (D051NG )
N a. the vessel's speed changed N b. the vessel's course changed form due North to due East Y c. running fixes are better estimates of true position than dead-reckoning positions N d. All of the above are correct 2372: In the North Sea area, you sight a buoy showing a quick white light showing 6 flashes followed by one long flash at 15 second intervals. Which of the four topmarks illustrated in diagram D031NG would be fitted to this buoy? (D031NG )
N a. A N b. B Y c. C N d. D 2510: When correcting apparent altitude to observed altitude, you do NOT apply a correction for __________.
N a. the equivalent reading to the center of the body N b. the equivalent reading from the center of the Earth N c. the bending of the rays of light from the body Y d. inaccuracies in the reference level 2576: What is the equivalent of 8 min. 56 sec. in arc units?
N a. 0°28' N b. 0°46' N c. 1°12' Y d. 2°14' 2584: You must construct a Mercator plotting sheet on a piece of paper measuring 30" by 36". The area includes latitude 30°45'S to 37°15'S and longitude 004°00'E to 005°00'W. Allow a one inch neat line on all sides. What is the maximum distance between each degree of longitude that will permit the area of the plotting sheet to be drawn within the stated limitation?
N a. 3.09 inches N b. 3.22 inches N c. 3.41 inches Y d. 3.58 inches 2714: A current moving across a lock entrance toward the river or toward the dam is called a(n) __________.
N a. cutoff Y b. outdraft N c. lockwash N d. springpool 2776: For a well made and well maintained sextant, the maximum value of which correction is usually so small that it can be ignored?
N a. Personal correction Y b. Instrument correction N c. Phase N d. Dip correction 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 3002: The diurnal variation of pressure is most noticeable __________.
N a. above the polar circles N b. in a low pressure area N c. during periods of low temperatures Y d. in the doldrums 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 3065: Raster-scan chart data is __________.
N a. the only format recognized by IMO/IHO N b. organized into many separate files N c. composed of files that are smaller than vector files Y d. a digitized "picture" of a chart in one format and one layer