T-Nav Exam 3

Front 1

Major Light:

Back 1

-a reliable, high-intensity light, which is shown from a fixed structure or from some marine site
-2 types: primary and secondary lights

Front 2

Primary Seacoast Lights:

Back 2

-used when sailing along a coastline and taking bearings on the principal lighthouses along the coast
-intended to facilitate coastwise navigation and also to be used for "making landfall"

Front 3

Secondary Lights:

Back 3

-situated at harbor entrances and other places where high-intensity, reliable lights are required, but are not primary seacoast lights

Front 4

Minor Light-

Back 4

always unmanned, is of low to moderate intensity, and is situated on a fixed structure

Front 5

All lighthouses exhibit:

Back 5

major lights

Front 6

Light Station-

Back 6

when a lighthouse is manned and has buildings round it to house personnel, sound signal apparatus, radiobeacon etc.

Front 7

Lightships-

Back 7

anchored, manned vessels that exhibit a light that is a navigational aid

Front 8

Purpose of a Station Buoy-

Back 8

-a much smaller buoy, and its purpose is to give an indication of whether or not the large navigational buoy has dragged anchor and changed buoy

Front 9

The Station Buoy is:

Back 9

not lighted and may be moored up to one mile away from the large nav buoy

Front 10

Anchor Buoys:

Back 10

-mark the anchors of floating oil rigs
-small spherical buoys are unlighted, and are sometimes at a considerable distance from the rig whose anchors they mark

Front 11

Fixed Lights:

Back 11

-exhibit a continuous steady light

Front 12

Rhythmic Lights-

Back 12

exhibit a sequence of intervals of light and eclipse (repeated at regular intervals)

Front 13

Alternating Lights-

Back 13

rhythmic lights which exhibit different colors during each sequence

Front 14

Meteorological Visibility:

Back 14

-the greatest distance at which a black object of suitable dimensions can be seen and recognized against the horizon sky or, in the case of night observations, could be seen and recognized if the general illumination were raised to the normal daylight level

Front 15

Luminous Range of Light:

Back 15

the greatest distance at which a light can be seen merely as a function of its luminous intensity, the meteorological visibility, and the sensitivity of the observer's eyes

Front 16

Nominal Range of Light-

Back 16

the luminous range of a light in a homogeneous atmosphere in which the meteorological visibility is 10 nautical miles

Front 17

Geographical Range of Light-

Back 17

the greatest distance at which a light can be seen as a function of the curvature of the earth, the height of the light source and the height of the observer

Front 18

Directional Lights-

Back 18

lights illuminating a sector of very narrow angle and intended to mark a direction to be followed

Front 19

Vertical Lights-

Back 19

2 or more lights disposed vertically or geometrically to form a triangle, square, or other figure

Front 20

Occasional Lights-

Back 20

-lights exhibited only when specially needed
-3 types

Front 21

3 Types of Occasional Lights:

Back 21

-tidal lights
-fishing lights
-private lights

Front 22

Tidal Lights-

Back 22

shown at the entrance of a harbor, to indicate tide and tidal current conditions within the harbor

Front 23

Fighing Lights-

Back 23

for the use of fishermen and shown when required

Front 24

Private Lights-

Back 24

maintained by a private authority for its own purposes

Front 25

Seasonal Lights-

Back 25

usually shown only during the navigation season or for a lesser time period within that season

Front 26

Articulated Lights-

Back 26

offshore aids to navigation consisting of a length of pipe attached directly to a sinker by means of a pivot or such other device employing the principle of the universal joint

Front 27

Aeronautical Lights-

Back 27

-lights of high intensity which may be the first lights observed at night from vessels approaching the coast
-these lights are not designed or maintained for marine navigation and they are subject to change without prompt notification

Front 28

Aeromarine Lights-

Back 28

marine-type lights for which part of the beam is deflected to an angle of 10-15deg above the horizon to facilitate use by aircraft

Front 29

Green Lights (aids to nav):

Back 29

-mark port sides of channels and locations of wrecks or obstructions which must be passed by keeping lighted aids to navigation on port hand of vessel
-also used on preferred channel marks where the preferred channel is to starboard

Front 30

Red Lights (aids to nav):

Back 30

-mark starboard sides of channels and locations of wrecks or obstructions which must be passed by keeping these lighted aids to nav on the starboard hand of vessel
-also used on preferred channel marks where the preferred channel is to port

Front 31

White and Yellow Lights:

Back 31

-have no lateral significance
-purpose of lights determined by shapes, colors, letters, and light rhythems

Front 32

Red or Green Retroflective Material:

Back 32

-used on lateral aids to navigation which, if lighted, will display lights of the same color

Front 33

Preferred Channel Marks:

Back 33

-exhibit a composite group-flashing light rhythm of 2 flashes followed by a single flash

Front 34

Safe Water Marks:

Back 34

-show a white Morse Code "A" rhythm (short flash followed by long flash)

Front 35

Isolated Danger Marks:

Back 35

-show a white flashing (2) rhythm (2 flashes repeated regularly)

Front 36

Special Marks:

Back 36

-show yellow lights and exhibit a flashing or fixed rhythm (flashing rhythm is preferred)

Front 37

Information and Regulatory Marks:

Back 37

-when lighted, display a white light with any light rhythm except quick flashing, flashing (2), and Morse code "A"

Front 38

Green Aids to Navigation:

Back 38

-odd numbers

Front 39

Red Aids to Navigation:

Back 39

-odd numbered

Front 40

Cylindrical Buoies:

Back 40

-can buoy
-paired with square dayboards, mark the left side of a channel when proceeding from seaward
-associated with solid green or green and red banded marks where the topmost band is green

Front 41

Conical Buoies:

Back 41

-nun buoy
-when paired with triangular dayboards mark the right side of the channel when proceeding from seaward
-associated with solid red or red and green banded marks where the topmost band is red

Front 42

Numbers of Buoies:

Back 42

increase from seaward

Front 43

Letters on Buoies:

Back 43

will increase from seaward

Front 44

Tide-

Back 44

vertical movement of water

Front 45

Current-

Back 45

horizontal movement of water

Front 46

Tidal Current-

Back 46

a current caused by tide

Front 47

What do the British call a tidal current?

Back 47

tidal stream

Front 48

Flood Current-

Back 48

rise of the tide

Front 49

Ebb Current-

Back 49

fall of the tide

Front 50

Two Main Causes of Tides:

Back 50

the gravitational effects of the sun and the moon

Front 51

Sublunar Point-

Back 51

the point on earth directly below the moon

Front 52

Antipode-

Back 52

the other point on the opposite side of the Earth, 180 deg away from the sublunar pt

Front 53

How long is a Lunar Day?

Back 53

24 hrs and 50 mins

Front 54

Spring Tide:

Back 54

-occur at full moon and new moon
-earth, moon and sun are all in alignment
-highest tides and lowest tides

Front 55

Neap Tides:

Back 55

-occur when the moon is "in quadrature" which is 1st or 3rd quarter
-lowest high tides
-highest low tides