National Maritime Center

Transcription

1 National Maritime Center Providing Credentials to Mariners Q191 Navigation General-Oceans (Sample Examination) Page 1 of 12

2 Choose the best answer to the following Multiple Choice Questions. 1. Under the U.S. Aids to Navigation System, a special mark possesses which of the following characteristics? (A) May show a yellow light with a flashing rhythm o (B) May show a light with the Morse code "A" rhythm o (C) Must be lighted with a fixed or flashing white light o (D) Must be lighted with a yellow isophase light 2. The velocity of the wind, its steady direction, and the amount of time it has blown determines what about a wind driven current? o (A) Its density o (B) Its deflection (C) Its speed o (D) Its temperature 3. The Light List shows that a navigational light has a nominal range of 12 miles and a height above water of 25 feet (7.6 meters). Your height of eye is 30 feet (9.1 meters) and the visibility is 0.5 mile. At what approximate range will you first sight the light? o (A) 5.2 miles o (B) 0.5 mile (C) 1.4 miles o (D) 12.0 miles 4. Which term is used to describe a generally circular low pressure area? (A) A cyclone o (B) A cold front o (C) An occluded front o (D) An anticyclone Page 2 of 12

3 5. In the IALA Buoyage System, what do buoys with alternating red and green horizontal bands indicate? (A) The preferred channel o (B) An isolated danger o (C) Fishing areas o (D) Spoil grounds 6. The magnitude of three stars is indicated. Which star is the brightest? (A) Canopus o (B) Vega o (C) Antares o (D) Cannot be determined; magnitude indicates size not brightness 7. The measurement of local time is based on the passage of the Sun over the. (A) lower branch of the observer's meridian o (B) upper branch of the observer's meridian o (C) upper branch of the Greenwich meridian o (D) lower branch of the Greenwich meridian 8. Under the IALA Buoyage Systems, which is TRUE of safe water marks? o (A) They must show a composite group-flashing, Fl(2 + 1), green light o (B) They may show a quick-flashing, Q(9)15s, white light o (C) They may show a composite group-flashing, Fl(2 + 1), red light (D) They may show a white Morse (A) light 9. The dry-bulb temperature is 78 F (26 C) and the wet-bulb temperature is 68 F (20 C). What is the relative humidity? o (A) 10% o (B) 24% o (C) 56% (D) 60% Page 3 of 12

4 10. When adjusting a magnetic compass for error, which is TRUE concerning the deviation table? (A) Construct the table after adjusting the fore-and-aft permanent magnets o (B) Construct the deviation table before correcting for any deviation o (C) Construct the deviation table before the quadrantal correctors are placed on the compass o (D) Construct the deviation table after correcting for variation 11. Which describes the precession of the equinoxes of the Earth? o (A) The the irregularity of the Earth's orbit caused by influences of the Sun and Moon o (B) The the gradual increase in the period of rotation caused by the effects of the Moon (C) The motion that is similar to a top spinning with its axis tilted o (D) The motion caused by the elliptical shape of the Earth's orbit 12. A great circle will intersect the equator at how many degrees of longitude apart? o (A) 45 (B) 180 o (C) 90 o (D) Which term describes a light, feathery deposit of ice caused by the sublimation of water vapor directly into the crystalline form, on objects whose temperatures are below freezing? o (A) Dew o (B) Snow (C) Frost o (D) Glaze 14. When using horizontal sextant angles of three objects to fix your position, an indeterminate position will result in which situation? o (A) The vessel is inside of a triangle formed by the objects. o (B) The objects lie in a straight line. o (C) The vessel is outside of a triangle formed by the objects. (D) A circle will pass through your position and the three objects. Page 4 of 12

5 15. Which best defines current? o (A) The vertical movement of the water o (B) The density changes in the water (C) The horizontal movement of the water o (D) None of the above 16. What weather change accompanies the passage of a cold front in the Northern Hemisphere? o (A) Steady precipitation, gradually increasing in intensity (B) A line of cumulonimbus clouds o (C) Wind shift from northeast clockwise to southwest o (D) Steady dropping of barometric pressure 17. Which term is used to describe the wind speed and direction observed from a moving vessel? o (A) The coordinate wind (B) The apparent wind o (C) The true wind o (D) The anemometer wind 18. What indicates that a tropical cyclone may be within 500 to 1,000 miles of your position? (A) A pumping of the barometer up and down a few millibars o (B) An overcast sky with steadily increasing rain from nimbostratus clouds o (C) A sudden wind shift from southwest to northwest followed by steadily increasing winds o (D) The normal swell pattern becoming confused, with the length of the swell increasing 19. Which meteorological feature controls the climate of the Gulf and the Gulf Coast area during late spring and summer? (A) The Bermuda High o (B) Tropical cyclones o (C) The doldrums o (D) The horse latitudes Page 5 of 12

6 20. Which condition indicates that you are in a hurricane's dangerous semicircle in the Northern hemisphere? o (A) A backing wind (B) A veering wind o (C) A strong, gusty wind o (D) A norther 21. You are proceeding up a channel at night. It is marked by a range which bears 185 T. You steady up on a compass course of 180 with the range in line dead ahead. This indicates that you(r). (A) compass has some easterly error o (B) must come right to get on the range o (C) are being affected by a southerly current o (D) course is in error 22. What results when warm moist air blows over a colder surface and is cooled below its dew point? (A) Advection fog o (B) Ice fog o (C) Frost smoke o (D) Radiation fog 23. With respect to a reversing current, slack water occurs when there is. o (A) when winds cause water to back up in a river mouth o (B) a weak ebb or flood current (C) little or no horizontal motion of the water o (D) little or no vertical motion of the water 24. You are enroute to assist vessel A. Vessel A is underway at 4.5 knots on course 233 T, and bears 346 T at 68 miles from you. What is the course to steer at 13 knots to intercept vessel A? o (A) 323 o (B) 318 o (C) 314 (D) 327 Page 6 of 12

7 25. Which term is given to the database resulting from (1) the transformation of the electronic navigational chart (ENC) by ECDIS for appropriate use, (2) the updates to the ENC by appropriate means, and (3) the additional data added by the mariner? (A) The system electronic navigational chart o (B) The display base information o (C) The chart display information o (D) The standard display information 26. Weather information provided by the National Weather Service (NWS) advisories should be used along with which other source of information? o (A) The local Notice to Mariners o (B) The Tide Tables and Tidal Current Tables (C) Weather maps and local knowledge o (D) Any U.S. Coast Pilot 27. At morning stars, the last stars that should be observed are those with an azimuth in which quadrant? o (A) Eastern o (B) Southern (C) Western o (D) Northern 28. Prior to reading an aneroid barometer, why should you tap the face lightly with your finger? o (A) To contract and expand the glass face o (B) To demagnetize the metal elements o (C) To expose any loose connections (D) To bring the pointer to its true position 29. How many fixed objects are needed to plot a running fix? o (A) None (B) One o (C) Two o (D) Three Page 7 of 12

8 30. Which statement about gyrocompass error is TRUE? o (A) Any error shown by a gyro repeater will be the same as the error of the master compass. o (B) The sign (E or W) of the error will change with different headings of the ship. o (C) Any error will remain constant unless the compass is stopped and restarted. (D) The amount of the error and the sign will generally be the same on all headings. 31. Where would you expect to find channels marked with the IALA-A Buoyage System? (A) Australia o (B) the Philippines o (C) Republic of Korea o (D) Chile 32. You sight a buoy fitted with a double-sphere topmark. If sighted at night, what color and light sequence would you expect to see? o (A) A quick-flashing red light o (B) A quick-flashing green light (C) A flashing white light showing a group of two flashes o (D) A flashing red light showing a group of three flashes 33. Information markers, when lighted, will display which color light? (A) White lights o (B) Red lights o (C) Green lights o (D) Yellow lights 34. ECDIS must give an alarm for which of the following cases? o (A) If the ship, within a specified time set by the watch officer, is going to cross the boundary of a prohibited area o (B) If the ship, within a specified time set by the watch officer, is going to cross a safety contour o (C) When the specified limit for deviation from the planned route is exceeded (D) All of the above Page 8 of 12

9 35. How can you follow the approach of a dangerous cyclonic storm? o o (A) Review the Coast Pilot or Sailing Directions (B) Utilizing the National Weather Service Observing Handbook No.1, Marine Surface Observations (C) By a newspaper, a weather map, a weather fax, or a weather forecast o (D) By monitoring the change in the sea temperature 36. Yesterday your chronometer read 11h 59m 59s at the 1200 GMT time tick. Today the chronometer reads 11h 59m 57s at the 1200 time tick. What is the chronometer rate? o (A) +3s o (B) -3s (C) -2s o (D) +2s 37. How can Northern right whales can be identified? o (A) Whitish patches of skin on top of the head o (B) "V" shaped blow easily visible from ahead or behind o (C) No dorsal fin on the back (D) All of the above 38. What do chart legends printed in capital letters indicate about the associated landmark? o (A) The landmark is inconspicuous o (B) It is a government facility or station o (C) The landmark has a radio transmitter (D) The landmark is conspicuous 39. Which maritime radio system consisting of a series of coast stations transmitting coastal warnings? (A) NAVTEX o (B) HYDROLANT/HYDROPAC o (C) SAFESEA o (D) NAVAREA Page 9 of 12

10 40. Mean lower low water is the reference plane used for which measurements? o (A) All vertical measurements o (B) The heights above water for lights, mountains, etc. o (C) The water depths on the U.S. east coast only (D) The soundings on the U.S. east and west coasts 41. What is a characteristic of cardinal marks? o (A) Square or triangular topmarks (B) Light rhythms indicating directional orientation o (C) Number-letter combinations for identification o (D) Vertical stripes 42. A latitude line will be obtained by observing a body. (A) at lower transit o (B) on the Greenwich meridian o (C) on the celestial horizon o (D) on the prime vertical 43. What can be expected with the presence of stratus clouds and a dying wind? o (A) Clearing skies o (B) Heavy rain o (C) Heavy snow (D) Thick fog 44. What are the colors of a mid-channel daymark? o (A) Green and red o (B) Black and red o (C) Green and white (D) Red and white Page 10 of 12

11 45. By convention, the Earth's south magnetic pole is which color? o (A) White o (B) Black o (C) Blue (D) Red 46. Temperature and moisture characteristics are modified in a warm or cold air mass due to which factor? o (A) Upper level atmospheric changes o (B) The heterogeneous nature of the air mass (C) Movement of the air mass o (D) Pressure changes in the air mass 47. When correcting the sextant altitude to apparent altitude you are correcting for inaccuracies in the reading and. (A) for inaccuracies in the reference level o (B) the equivalent reading from the center of the Earth o (C) the bending of the rays of light from the body o (D) the equivalent reading at the center of the body 48. What do red sectors of navigation lights warn mariners of? o (A) Heavily trafficked areas (B) Shoals or nearby land o (C) Recently sunken vessels o (D) Floating debris 49. At which interval should a tradional spring driven marine chronometer be rewound? o (A) Every 12 hours (B) Once a day o (C) Once every 3 days o (D) Once a week Page 11 of 12

12 50. In some parts of the world there is often a slight fall in tide during the middle of the high water period. The effect is to create a longer period of stand at higher water. This special feature is called a(n). o (A) perigean tide o (B) bore o (C) apogean tide (D) double high water Page 12 of 12