get to know the terms used in fisheries navigation .

1. FS-313: NAVIGATION ANDSEAMANSHIP
S.NO: TERMS: DEFINITION:
1) AZIMUTH: An instrument used to determine the altitude of celestial objects
before the introduction of the sextant , the first recorded use by
Greek astronomers in around 200 BC.
2) ALTITUDE: The angular distance of a celestial body above the viewers horizon.
3) AGROUND: Resting on or touching the ground or bottom.
4) ANCHOR: An object designed to prevent or slow the drift of a ship, attached to
the ship by a line or chain; typically a metal, hook like, object
designed to grip the bottom under the body of water.
5) ANCHORAGE: A suitable place for a ship to anchor. Area of a port or harbor.
6) BEARING: The compass reading taken of a object in relation to the observer.
7) BINNACLE: The stand on which the ship's compass is mounted.
8) BULWARK: The extension of the ship's side above the level of the weather deck.
9) BILGE: The lowest inner part of a ships hull. bilge water accumulates in the
bilge.
10) BREECHES BUOY: used to transfer person from a disable ship to either rescue ship or
to shore
11) CARDINAL
POINTS:
The four main parts of the compass, North, South, East, West.
12) CARDINAL
POINTS:
Buoyage marks indicating the direction of safe water with reference
to the cardinal points.
13) COMPASS
ERROR:
The angular difference between true north and compass north.
14) CHART: A map of the sea , showing any coastal lines and used specifically for
nautical navigation.

2. FS-313: NAVIGATION ANDSEAMANSHIP
15) COURSE: horizontal distance in which a vessel is steered or intended to be
steered.
16) DUNNAGE: Loose packing material used to protect a ship's cargo from damage
during transport. Personal baggage.
17) DEVIATION: The angular difference between compass north and magnetic north.
18) DOCKING: The procedure for coming alongside and securing to a wharf or jetty.
19) DEAD
RECKONING:
Is fixing of present position or expected future position, from a
previous position using known direction and distances.
20) EQUATOR: The great circle whose plane is perpendicular to the polar axis,
midway between the poles.
21) ECHO GRAM: Visual record of reflected echoes of sound transmitted by an echo
sounder
22) FATHOM: A unit of measure equal to six feet, used to describe depth of water,
or length of rope or line.
23) FETCH: The distance over water which the wind has blown uninterrupted.
24) FIX: A relatively accurate position determined without reference to any
former position.
25) FLARE: A signal device to indicate distress, the external concave curve of
the bow of a ship
26) GROUND
TACKLE:
A collective term used to embrace all of the gear used for anchoring
or for securing a navigation buoy to the bottom.
27) GYRO COMPASS: A directional instrument that indicates gyro north, which can be
very close to true north.
28) GALLEY: The kitchen in a ship or aircraft.
29) HEADING ( SHIPS
HEAD)
Is constantly changing value as ship oscillates or yaws across due to
effects of sea & steering error.(or) the direction in which the ships
head is pointed.
30) HALYARD: A rope used for hoisting sails, spars or flags.

3. FS-313: NAVIGATION ANDSEAMANSHIP
31) KNOT: A unit of speed equal to one nautical mile per hour.
32) KELLET: A heavy weight attached in the length of the anchor rope to reduce
the angle of pull on the anchor.
33) LATITUDE: The angular distance of a point on the surface of the earth north or
south of the equator as measured at the centre of the earth.
34) LEE SIDE: The side opposite to the direction from which the wind blows.
35) LIGHT HOUSE: A major light built as a manmade aid to navigation; may be manned
or unmanned.
36) LOP(LINE OF
POSITION):
A line on the chart along which the vessel is known to lie.
37) LOG: A device that measures distance travelled through the water, from
which speed can be calculated.
38) LONGITUDE: The angular distance east or west of prime meridian of the prime
meridian of a point on the surface of the earth as measured at the
polar axis.
39) LUBBER LINE: The reference line of a compass.
40) MAGNETIC
COMPASS:
A directional instrument actuated by the earths magnetic field.
41) MAY DAY : Mayday is an emergency procedure word used internationally as a
distress signal in voice procedure radio communications.
42) MEDEVAC: Includes evacuation of a person from a vessel for medical reasons.
43) MERCATOR
PROJECTION:
The most common type of chart projection used for navigational
charts.
44) MERCATOR
CHART:
A cylindrical map projection in which the meridian and parallel
appear as lines crossing at right angles and in which areas appear
greater farther from the equator.
45) MERIDIAN: An imaginary line joining the earths poles ,the prime meridian is the
one that passes through Greenwich, England and represents zero
longitude.
46) MAST HEAD
LIGHT:
white light placed at centre over an arc of horizon of225deg
&22.5deg abaft the beam on either side.

4. FS-313: NAVIGATION ANDSEAMANSHIP
47) NAVIGATION: process of directing or conducting the movement of a vehicle
/vessel from one place to another safely.
48) PELORUS: The navigation instrument used for taking visual bearings, having a
card and an arc rotating sight bar with two sighting vanes.
49) PILOTING: Is navigating, using fixed points of reference on the sea or on land ,
usually with reference to a nautical chart or aeronautical chart to
obtain a fix of the position of the vessel or aircraft with respect to a
desired course or location.
50) PLOT: To draw lines on a chart indicating bearings, courses and positions.
51) RUNNING FIX: A position determined by the use of bearings that have an
appreciable time difference in between them.
52) RHUMB LINE: a line crosses every meridian of sphere at same angle.
53) STERN LIGHT: white light, unbroken over an arc of horizon of 135deg &67.5deg
each side.
54) SIDE LIGHT: green light, unbroken over an arc of horizon of 112.5 deg&52.5deg
abaft the beam.
55) SKIPPER: The person in command of a vessel.
56) SEMAPHORE: Signalling by hand flags or arms.
57) SEASMANSHIP: The skill , techniques ,or practices of handling a ship or boat at sea.
58) TRUE WIND: The direction and velocity of the wind as observed from a stationary
point
59) UNDERWAY: A vessel when not at anchor, aground or made fast to shore.
60) VARIATION: The angular difference between magnetic north and true north.