Nav General
Coast Pilots and navigational charts are kept corrected and up-to-date by using the __________. (A) Notices to Mariners (B) Current Tables (C) Tide Tables (D) pilot charts
(A) Notices to Mariners
What instrument measures wind velocity? (A) Hydrometer (B) Psychrometer (C) Barometer (D) Anemometer
(D) Anemometer
A vessel crossing the international date line in an Easterly direction, would? Lose a day Gain a Day Stay the Same Is the same as crossing any other time zone, unless it is 2359
Gain a Day
When an observer, who is north of the sun, is calculating LAN in the northern hemisphere the formula for determining latitude is ________________. Z - Dec. Z - Dec. Z + Dec. Z - Nadir
Z + Dec.
To predict the actual depth of water using the tide tables, the number obtained from the tide tables is ______________. a. divided by the charted depth b. multiplied by the charted depth c. added to or subtracted from the charted depth d. the actual depth
c. added to or subtracted from the charted depth
Your vessel is steering a course of 010T. Variation is 12W. Fetermine your magnetic course. a. 22T b. 2E c. 22N d. 22M
d. 22M
The USCG's preferred electronic chart type is (A) Offical ENC (B) DNC (C) vector (D) raster
(A) Offical ENC
The celestial body most often used for azimuth by altitude is: (A) The sun (B) Polaris (C) Moon (D) Regulus
(A) The sun
When you are steering on a pair of range lights and find the upper light is above the lower light you should __________. (A) continue on the present course (B) come right (C) come left (D) wait until the lights are no longer in a vertical line
(A) continue on the present course
A green buoy has a yellow triangle on it. This is a(n) __________. (A) dual purpose marking used where the ICW and other waterways coincide (B) buoy that was set in error and will be replaced with a red nun buoy (C) information or regulatory buoy that has lateral significance (D) buoy that is off-station and is marked to warn mariners of its wrong position
(A) dual purpose marking used where the ICW and other waterways coincide
The shortest route between two points on the earth is a (A) great-circle route (B) rhumb-line route (C) dead-ahead route (D) spheroid
(A) great-circle route
With respect to a reversing current, slack water occurs when there is __________. (A) little or no horizontal motion of the water (B) a weak ebb or flood current (C) when winds cause water to back up in a river mouth (D) little or no vertical motion of the water
(A) little or no horizontal motion of the water
The quadrantal spheres are used to __________. (A) remove deviation on the intercardinal headings (B) remove heeling error (C) compensate for induced magnetism in vertical soft iron (D) remove deviation on the cardinal compass headings
(A) remove deviation on the intercardinal headings
On a mercator projection chart, parallels and meridians are straight lines that meet at (A) right (90�) angles (B) large (>90�) angles (C) they do not meet (D) meridians plot as curved lines
(A) right (90�) angles
In a cardinal system, buoys are generally used to covey: (A) The sides of a navigable channel (B) A geographic relationship with a hazard in terms of 90-degree quadrants (C) The most efficient route within the restricted waters of a port (D) The junctions and bifurcations within a channel
(B) A geographic relationship with a hazard in terms of 90-degree quadrants
The azimuth circle must be kept __________ to ensure an accurate measurement of compass azimuth. (A) Vertical (B) Horizontal (C) In a cool dry place (D) Well greased
(B) Horizontal
Gyrocompass repeaters reproduce the indications of the master gyrocompass. They are __________. (A) hand operated (B) accurate electronic servomechanisms (C) accurate only in the Polar regions (D) accurate only if the vessel is underway
(B) accurate electronic servomechanisms
A vessel's position should be plotted using bearings of __________. (A) fixed objects (B) fixed known objects on shore (C) buoys close at hand (D) All of the above
(B) fixed known
Under the IALA-B Buoyage System, when entering from seaward, a buoy that should be left to port will be __________. (A) red (B) green (C) black (D) yellow
(B) green
Your vessel is "on range" in a channel. The chart indicates that the range is 020°T. Your gyro compass reads 022°pgc. Your gyro-compass error is: (A) 358° E (B) 002° E (C) 002° W (D) 042° W
(C) 002° W
Azimuth observations should be made when the Sun is in low altitude and preferably less than ______ degrees above the horizon. (A) 35 (B) 45 (C) 20 (D) 10
(C) 20
Which of the following means of determining gyro compass error is the simpilist to accomplish? (A) Azimuth (B) Amplitude (C) Terrestrial Range (D) Course Made Good
(C) Terrestrial Range
Where will you find information about the duration of slack water? (A) Sailing Directions (B) American Practical Navigator (C) Tidal Current Tables (D) Tide Tables
(C) Tidal Current Tables
A current perpendicular to a vessel's track has the greatest effect on the vessel's course made good __________. (A) at high vessel speeds (B) in deep water (C) at low vessel speeds (D) in shallow water
(C) at low vessel speeds
When recording the wind direction in the weather log, you would report the __________. (A) duration of the maximum gust of wind (B) wind chill factor (C) direction the wind is blowing from (D) direction the wind is blowing toward
(C) direction the wind is blowing from
When a current flows in the opposite direction to the waves, the wave __________. (A) length is unchanged (B) velocity increases (C) height is increased (D) length is increased
(C) height is increased
When taking an amplitude, the Sun's center should be observed on the visible horizon when __________. (A) the declination is of a different name from the latitude (B) the Sun is near or at a solstice (C) in high latitudes (D) the Sun's declination is at or near 0
(C) in high latitudes
Variation is the angular measurement between __________. (A) your vessel's heading and the magnetic meridian (B) compass north and true north (C) magnetic meridian and the geographic meridian (D) compass north and magnetic north
(C) magnetic meridian and the geographic meridian
The reference datum used in determining the heights of land features on most charts is __________. (A) half-tide level (B) mean sea level (C) mean high water (D) mean low water
(C) mean high water
In North America the majority of the weather systems move from __________. (A) south to north (B) east to west (C) west to east (D) north to south
(C) west to east
Air masses near the earth's surface __________. (A) move from areas of high pressure to areas of low pressure (B) are deflected by the "Coriolis effect" (C) are deflected by the earth's rotation in both hemispheres (D) All of the above
(D) All of the above
The buoy symbol on a chart is used to indicate the _____________ position of the buoy. (A) Exact (B) Mean low water (C) Mean low low water (D) Approximate
(D) Approximate
Azimuth observations of celestial bodies are made by use of a: (A) Sextant (B) Star finder (C) Stella (D) Azimuth circle
(D) Azimuth circle
What happens to the barometric pressure after a cold front passes? (A) rises, and the temperature rises (B) drops, and the temperature rises (C) drops, and the temperature drops (D) rises, and the temperature drops
(D) rises, and the temperature drops
The Zone Descriptor for New London, CT on 1/15/2016 is? EST EDT +5R -5R
+5R
Polaris is located less than ___________________ from the north celestial pole. 1 degree 5 degrees 15 degrees 60 degrees
1 degree
15 minutes of longitude is equal to _________ of time. 30 minutes 1 minute 15 minutes 1 hour
1 minute
The sun changes longitude at an hourly rate of ______________. 30 degrees 15 degrees 4 degrees 1 degree
15 degrees
The earth's axis is inclined at an angle of about_______. (A)23.5 degrees (B)15 degrees (C)1 degree (D)2.5 degrees
23.5 degrees
There are _______________ between the celestial horizon and the observer's zenith. 180 degrees 35 degrees 60 degrees 90 degrees
90 degrees
The equation of coaltitude is: 90o - Altitude of the body 90o + Altitude of the body 90o - declination 90o - latitude
90o - Altitude of the body
The equation of colatitudes is: 90o - latitude 90o - declination 90o - Altitude of the body 90o - azimuth angle
90o - latitude
The primary purpose of a Polaris observation in celestial navigation is to determine _________________ A latitude line of position A navigational fix A celestial hour circle A celestial hour angle
A latitude line of position
The field of stars that surround earth and appear to rotate around the plant is known as the ___________. (A)Galaxy (B)Regulus (C)Celestial sphere (D)Zenith Nadir
Celestial Sphere
The three points of the navigational triangle are: Geographic position, observer's zenith, and celestial equator Geographic position, observer's zenith, and celestial horizon Geographic position, celestial zenith, and celestial equator Geographic position, observer's zenith, and celestial pole
Geographic position, observer's zenith, and celestial pole
The point on earth directly below a celestial body is the __________. (A)geographical position (B)declination (C)latitude of the body (D)celestial position
Geographical Position
What coordinate system is utilized when attempting to determine the height of the sun with a marine sextant for a LAN calculation? Terrestrial coordinate system Celestial coordinate system Horizon coordinate system All of the above
Horizon coordinate system
For navigators, the equivalent of longitude within the celestial equator system of coordinates is: Equinoctial Declination Celestial altitude Hour angle
Hour angle
"Ho" equals: IC + dip + declination IC + dip + latitude Hs + IC + dip + altitude correction IC + dip + celestial horizon
Hs + IC + dip + altitude correction
Declination of a celestial body is identical to the __________ of the geographic position. (A)longitude (B)GHA (C)tabulated angle (D)latitude
Latitude
In the navigational triangle the observer's actual position is labeled: Z GP Pn M
M
When conducting a Polaris observation one must still account for ________ to accurately calculate latitude. Refraction Leap year Nadir GHA
Refraction
Colatitude is derived from the ___________ coordinate system. Terrestrial Celestial equator Celestial horizon Observer's hour angle
Terrestrial
If a star were located exactly at each celestial pole, the corrected altitude of the star would equal __________. The observer's longitude The apparent position of the observer The geographic position of the observer. The oberserver's latitude.
The oberserver's latitude.
In a 24 hour period, how often is Polaris at the same altitude as the pole? Once Twice Never Always
Twice
What time is used as the standard for electronic navigation systems like GPS wordwide? LMT Zulu GMT UTC
UTC
Sunrise is defined as the first appearance of the sun's____________ above the horizon. Lower Limb Center Upper Limb Diameter
Upper Limb
Your vessel is steering on a terrestrial range of 010T. Your gyro compass reads 012pgc. determine gyro error a. 2W b. 2E c. 2N d. 22
a. 2W
An azimuth circle works by projecting a single line of light from a celestial body onto a _____________________. a. compass card b. mercator card c. pelorus d. repeater
a. compass card
An isophase light characteristic is: a. light with all durations of light and darkness equal b. shows a series of 6 quick flashes repeated at intervals of 10 seconds c. showing at regular intervals groups of 2 or more flashes d. a continous stead light
a. light with all durations of light and darkness equal
When a hurricane passes over colder water or land and loses its tropical characteristics, the storm becomes a(n) _________________. a. tropical storm b. extratropical low-pressure system c. easterly wave d. high pressure area
b. extratropical low-pressure system
which of the following is the most accurate method of determing gyrocompass error while underway? a. determing from the chart the course made good between celestial fixes b. comparing the gyro azimuth of a celestial body with the computed azimuth of the body c. comparing the gyro heading with the magnetic compass heading d. it cannot be determined accurately at sea due to drift of unknown currents
b. comparing the gyro azimuth of a celestial body with the computed azimuth of the body
Distance along a track line is measured on a Mercator chart by using the __________. a. latitude scale at the mid latitude of the chart b. latitude scale near the middle of the track line c. latitude of longitude scale at the middle of the scale d. longitude scale near the middle of the track line
b. latitude scale near the middle of the track line
The period at high or low tide during which there is no change in the height of the water is called the __________________. a. reversing of the tide b. stand of the tide c. plane of the tide d. range of the tide
b. stand of the tide
The period at high or low tide during which there is no change in the heigt of the water is called the ____________. a. reversing of the tide b. stand of the tide c. plane of the tide d. range of the tide
b. stand of the tide
The speed of an ocean current is dependent on ______________. a. underwater soil conditions b. the density of the water c. the presence of a high pressure area near it d. the air temperature
b. the density of the water
Assuming gyro error is 0, the compass card of the gyro-compass points toward a. true west b. true north c. magnetic north d. aries
b. true north
which statement about a gnomic chart is correct? a. distance is measured at the mid-latitude of the track line b. a rhumb line appears as a straight line c. parallels, except the equator, appear as curved lines d. meridians appear as curved lines converging toward the nearer ple
c. parallels, except the equator, appear as curved lines
Which indication of the barometer is most meaningful in forecasting weather? a. the words "fair - change - ran" b. the relative humidity c. the direction and rate of change of barometric pressure d. the actual barometic pressure
c. the direction and rate of change of barometric pressure
Charted depth is the _____________. a. average hieght of water over a specified period of time b. average height of all low waters at a place c. vertical distance from the charted sounding datum to the ocean bottom d. vertical distance from the chart sounding datum to the ocean bottom, plus heigh of tide
c. vertical distance from the charted sounding datum to the ocean bottom
safe water buoys may show only ______________. a. flahshing green lights b. yellow lights c. white lights d. flashing red lights
c. white lights
You are sailing south on the intracoastal waterway (ICW) when you sight a red nun bouy with a yellow square painted on it. Which statement is true? a. the waterway in that area has shoaled and the available depth of water is less than the project depth b. the buoy is off station and should be ignored as a navigational mark c. you should leave the buoy to port d. ICW traffic should not proceed beyond the buoy unless the crossing waterway is clear of all traffic
c. you should leave the buoy to port
ECDIS must give an alarm for which of the following cases? a. if the ship, within a specified time set by the watch officer, is going to cross the boundary of a prohibited area b. when the specified limit for deviation from the planned route is exceeded c. if the ship, within a specified time set by the watch officer, is going to cross a safety contour d. all of the above
d. all of the above
Ocean currents are well defined and ______________. a. are characterized by a light green color b. change direction 360 degrees during a 24 hour period c. create large waves in teh direction of teh current d. remain fairly constant in direction and velocity throughout the year
d. remain fairly constant in direction and velocity throughout the year
What is the definition of height of tide? a. the veritcal difference between a datum plane and the ocean bottom b. the vertical distance from the surface of the water to the ocean floor c. the vertical difference between the heights of low and hgih water d. the vertical distance from the tidal datum to the level of the water at any time
d. the vertical distance from the tidal datum to the level of the water at any time
Where can information about the currents for the Pacific Coast of the U.S. be obtained? a. tide tables b. nautical almanac c. ocean current tables d. tidal current tables
d. tidal current tables
