CHARTS & NAVIGATIONCHARTS & NAVIGATIONCHARTS & NAVIGATIONCHARTS & NAVIGATION

LATITUDELATITUDELATITUDELATITUDELATITUDESLATITUDESLATITUDESLATITUDES

LONGITUDESLONGITUDESLONGITUDESLONGITUDES

• • LINES PARALLEL TO EQUATORLINES PARALLEL TO EQUATOR

• • CONCENTRIC CIRCLES OF DIFFERENT SIZESCONCENTRIC CIRCLES OF DIFFERENT SIZES

• • PARALLELS (Lines) – INCREASE NORTH & PARALLELS (Lines) – INCREASE NORTH & SOUTH OF SOUTH OF EQUATOR (0°) FROM ZERO TO 90°EQUATOR (0°) FROM ZERO TO 90°

• • CAN BE DETERMINED BY USING A SEXTANTCAN BE DETERMINED BY USING A SEXTANT

• • LINES PARALLEL TO EQUATORLINES PARALLEL TO EQUATOR

• • CONCENTRIC CIRCLES OF DIFFERENT SIZESCONCENTRIC CIRCLES OF DIFFERENT SIZES

• • PARALLELS (Lines) – INCREASE NORTH & PARALLELS (Lines) – INCREASE NORTH & SOUTH OF SOUTH OF EQUATOR (0°) FROM ZERO TO 90°EQUATOR (0°) FROM ZERO TO 90°

• • CAN BE DETERMINED BY USING A SEXTANTCAN BE DETERMINED BY USING A SEXTANT

• • LINES RUN FROM POLE TO POLELINES RUN FROM POLE TO POLE

• • ALL SAME LENGTHALL SAME LENGTH

• • MERIDIANS (LINES) – INCREASE WEST & EAST OF MERIDIANS (LINES) – INCREASE WEST & EAST OF PRIME MERIDIAN (0°) FROM ZERO TO 180° PRIME MERIDIAN (0°) FROM ZERO TO 180°

• • CAN BE DETERMINED with a CHRONOMETER CAN BE DETERMINED with a CHRONOMETER (CALIBRATED TO GREENWICH MEAN TIME)(CALIBRATED TO GREENWICH MEAN TIME)

• • LINES RUN FROM POLE TO POLELINES RUN FROM POLE TO POLE

• • ALL SAME LENGTHALL SAME LENGTH

• • MERIDIANS (LINES) – INCREASE WEST & EAST OF MERIDIANS (LINES) – INCREASE WEST & EAST OF PRIME MERIDIAN (0°) FROM ZERO TO 180° PRIME MERIDIAN (0°) FROM ZERO TO 180°

• • CAN BE DETERMINED with a CHRONOMETER CAN BE DETERMINED with a CHRONOMETER (CALIBRATED TO GREENWICH MEAN TIME)(CALIBRATED TO GREENWICH MEAN TIME)

LONGITUDELONGITUDE

EQUATOREQUATORImaginary line dividing our planet into northern & Imaginary line dividing our planet into northern &

southern hemispheressouthern hemispheres

pp

Equator 0°

THE EARTH’S GRIDTHE EARTH’S GRID

PRIME MERIDIAN: ESTABLISHED 1884 AT GREENWICH, PRIME MERIDIAN: ESTABLISHED 1884 AT GREENWICH, ENGLANDENGLAND

15° Longitude = One hour of Earth’s Rotation15° Longitude = One hour of Earth’s Rotation

PRIME MERIDIAN STAND WITH ONE FOOT IN WESTERN & ONE IN EASTERN

HEMISPHERE

PRIME MERIDIAN STAND WITH ONE FOOT IN WESTERN & ONE IN EASTERN

HEMISPHERE

GREENWICH, ENGLANDGREENWICH, ENGLAND

GPS shows the GPS shows the longitude to be longitude to be W 000° 00’ 00.0”W 000° 00’ 00.0”Indicating theIndicating thePrime MeridianPrime Meridian

THE INTERNATIONAL DATE LINE (IDL)THE INTERNATIONAL DATE LINE (IDL)

•OPPOSITE THE PRIME MERIDIAN, AT OPPOSITE THE PRIME MERIDIAN, AT 180°180°

•NOT A STRAIGHT LINENOT A STRAIGHT LINE

•ALTERED TO BE CONSISTENT WITH ALTERED TO BE CONSISTENT WITH LOCAL ISLAND GEOGRAPHYLOCAL ISLAND GEOGRAPHY

Prime Meridian

THE NORTH POLETHE NORTH POLETHE NORTH POLETHE NORTH POLE• Earth's magnetic field (metallic core with magnetite): Earth's magnetic field (metallic core with magnetite): 2 2 magnetic poles (MP):magnetic poles (MP):

1.) North MP (in Canadian arctic) 1.) North MP (in Canadian arctic) 2.) South MP (off Antarctica’s coast, south of 2.) South MP (off Antarctica’s coast, south of Australia)Australia)

•North MP is slowly drifting across Canadian ArcticNorth MP is slowly drifting across Canadian Arctic

•Canadian Geological Survey tracks motion with magnetic surveys Canadian Geological Survey tracks motion with magnetic surveys to determine pole's locationto determine pole's location

• Earth's magnetic field (metallic core with magnetite): Earth's magnetic field (metallic core with magnetite): 2 2 magnetic poles (MP):magnetic poles (MP):

1.) North MP (in Canadian arctic) 1.) North MP (in Canadian arctic) 2.) South MP (off Antarctica’s coast, south of 2.) South MP (off Antarctica’s coast, south of Australia)Australia)

•North MP is slowly drifting across Canadian ArcticNorth MP is slowly drifting across Canadian Arctic

•Canadian Geological Survey tracks motion with magnetic surveys Canadian Geological Survey tracks motion with magnetic surveys to determine pole's locationto determine pole's location

•May 2001’s survey: May 2001’s survey:

•Pole moving NW ~24 miles/yearPole moving NW ~24 miles/year

• Nautical charts must be updated so Nautical charts must be updated so compasses may be used compasses may be used

•Magnetic north pole movesMagnetic north pole moves

• GPS is replacing compassGPS is replacing compass

•More accurate navigational tool More accurate navigational tool

NORTH POLE NORTH POLE NORTH POLE NORTH POLE SOUTH POLE SOUTH POLE SOUTH POLE SOUTH POLE

PATH OF THE MAGNETIC NORTH POLE PATH OF THE MAGNETIC NORTH POLE FROM 1600 TO 2000 – MOVES ABOUT 24 FROM 1600 TO 2000 – MOVES ABOUT 24 MILES A YEARMILES A YEAR

PATH OF THE MAGNETIC NORTH POLE PATH OF THE MAGNETIC NORTH POLE FROM 1600 TO 2000 – MOVES ABOUT 24 FROM 1600 TO 2000 – MOVES ABOUT 24 MILES A YEARMILES A YEAR

THE CHARTTHE CHARTTHE CHARTTHE CHART

SCALESCALE: relationship between the distance of 2 points represented on : relationship between the distance of 2 points represented on a chart & the same 2 points in the real world a chart & the same 2 points in the real world

Usually referred to by a ratio:Usually referred to by a ratio:EX:EX: 1:40,000 1:40,000 1 inch (on chart) = 40,000 inches (real 1 inch (on chart) = 40,000 inches (real

world) world)

SCALESCALE: relationship between the distance of 2 points represented on : relationship between the distance of 2 points represented on a chart & the same 2 points in the real world a chart & the same 2 points in the real world

Usually referred to by a ratio:Usually referred to by a ratio:EX:EX: 1:40,000 1:40,000 1 inch (on chart) = 40,000 inches (real 1 inch (on chart) = 40,000 inches (real

world) world)

SYMBOLS:SYMBOLS: Indicate buoys, lights, foghorns, markers, whistles, etc. Indicate buoys, lights, foghorns, markers, whistles, etc.SYMBOLS:SYMBOLS: Indicate buoys, lights, foghorns, markers, whistles, etc. Indicate buoys, lights, foghorns, markers, whistles, etc.

COMPASS ROSECOMPASS ROSE - Circle within a circle used to indicate direction: - Circle within a circle used to indicate direction: Both have degrees on them from 0° to 360°Both have degrees on them from 0° to 360°Outer circle points to “true” north (gives true bearing) Outer circle points to “true” north (gives true bearing) Inner circle points to magnetic north (gives magnetic bearing)Inner circle points to magnetic north (gives magnetic bearing)

COMPASS ROSECOMPASS ROSE - Circle within a circle used to indicate direction: - Circle within a circle used to indicate direction: Both have degrees on them from 0° to 360°Both have degrees on them from 0° to 360°Outer circle points to “true” north (gives true bearing) Outer circle points to “true” north (gives true bearing) Inner circle points to magnetic north (gives magnetic bearing)Inner circle points to magnetic north (gives magnetic bearing)

LATITUDE & LONGITUDELATITUDE & LONGITUDE - Marked along edges of nautical charts, - Marked along edges of nautical charts, indicating degrees, minutes, & secondsindicating degrees, minutes, & secondsLATITUDE & LONGITUDELATITUDE & LONGITUDE - Marked along edges of nautical charts, - Marked along edges of nautical charts, indicating degrees, minutes, & secondsindicating degrees, minutes, & seconds

Reading charts

Contour linesContour lines

DepthDepthFt., Meters,FathomsFt., Meters,Fathoms

SymbolsSymbols

R9QTHK

Nautical chartNautical chart

Latitude & Longitude are Latitude & Longitude are marked along chart edgesmarked along chart edgesLatitude & Longitude are Latitude & Longitude are marked along chart edgesmarked along chart edges

Always find these on chart:Always find these on chart:

1. Scale 1. Scale 2. Depth (Ft., Fathom, 2. Depth (Ft., Fathom, Meters) Meters) 3. Contour Lines3. Contour Lines 4. Compass Rose4. Compass Rose 5. Symbols5. Symbols 6. Latitude & Longitude6. Latitude & Longitude

THE COMPASS ROSETHE COMPASS ROSE

• A circle within a circle A circle within a circle used to indicate directionused to indicate direction

•Both have degrees from Both have degrees from 0° to 360°0° to 360°

•Outer circleOuter circle points to points to geographic or true north geographic or true north (north pole) & gives true (north pole) & gives true bearingbearing

•Inner circleInner circle points to points to magnetic north (in Canada) magnetic north (in Canada) & gives a magnetic bearing & gives a magnetic bearing

•Also shows the variation & Also shows the variation & annual increaseannual increase

Indicates True NorthIndicates True North

Indicates Magnetic NorthIndicates Magnetic North

VariationVariation

Annual increaseAnnual increase

DEGREES, MINUTES, & SECONDSDEGREES, MINUTES, & SECONDS

1 MINUTE1 MINUTE

1 1 DEGREEDEGREE

40° 50'

51'

52'

53'

54'

55'

01'

02'

03'

04'

05'

06'

07'

41° 00'

12 12 SEC0NDSSEC0NDS

YOU WILL DETERMINE YOU WILL DETERMINE DEGREES, MINUTES, & DEGREES, MINUTES, & SECONDS ON THE SECONDS ON THE CHART (CAN VARY ON CHART (CAN VARY ON DIFFERENT CHARTS)DIFFERENT CHARTS)

LONGITUDES ARE READ LONGITUDES ARE READ THE SAME WAY AS THE SAME WAY AS THESE LATITUDE THESE LATITUDE READINGSREADINGS

60 seconds in a minute

PLOTTING INSTRUMENTSPLOTTING INSTRUMENTS

USING THE PARALLEL RULERSUSING THE PARALLEL RULERS

Parallel rulers allow you to follow a line Parallel rulers allow you to follow a line accuratelyaccurately

Connect 2 points Connect 2 points Use with Compass RoseUse with Compass Rose

22

11

33 44

DIVIDERSDIVIDERSDividers can be used to determine nautical miles Dividers can be used to determine nautical miles

(nautical mile scale on chart)(nautical mile scale on chart)

CHART PROJECTIONSCHART PROJECTIONS(Show a representation of the globe)(Show a representation of the globe)

MERCATOR PROJECTIONMERCATOR PROJECTION•Most commonly used projection on nautical chartsMost commonly used projection on nautical charts

•Benefits:Benefits: •Lines of longitude & latitude intersect at right angles, so Lines of longitude & latitude intersect at right angles, so directions can be plotted accuratelydirections can be plotted accurately

•Shape of an object is accurately representedShape of an object is accurately represented•Disadvantage:Disadvantage: As you go towards the poles, objects appear As you go towards the poles, objects appear larger than they actually arelarger than they actually are

•Other projections (Gnomonic, Orthographic, Robinson)Other projections (Gnomonic, Orthographic, Robinson)

SOME USEFUL NUMBERSSOME USEFUL NUMBERS• Statute mile = 5,280 feet, Nautical mile = 6,076.12 feet Statute mile = 5,280 feet, Nautical mile = 6,076.12 feet

• • Statute miles x 0.87 = nautical miles Statute miles x 0.87 = nautical miles

• • Nautical miles x 1.15 = statute miles Nautical miles x 1.15 = statute miles

1. Nautical miles - ocean & coastal waters1. Nautical miles - ocean & coastal waters

2. Statute miles - inland areas (river, lake)2. Statute miles - inland areas (river, lake)

• A Nautical MileA Nautical Mile = 1/60th of a degree or 1 minute of latitude = 1/60th of a degree or 1 minute of latitude

•Use this phrase:Use this phrase: "A minute's a mile the world around.” "A minute's a mile the world around.”

• • One degreeOne degree of latitude = 60 nautical miles (All of Earth) of latitude = 60 nautical miles (All of Earth)

• Each degreeEach degree is divided up into 60 minutes is divided up into 60 minutes

• Each minuteEach minute is further carved into either 60 seconds or is further carved into either 60 seconds or decimal decimal minutesminutes

Coordinates of OCC Marine Science Department:Coordinates of OCC Marine Science Department:

Latitude: 33° 38’ 22” North Longitude: 117° 25’ 15” West Latitude: 33° 38’ 22” North Longitude: 117° 25’ 15” West

•1 fathom = 6 feet = 1.8288 meters1 fathom = 6 feet = 1.8288 meters

••Nautical charts are updated every 2 years, on avg (6 mos. – 12 yrs.)Nautical charts are updated every 2 years, on avg (6 mos. – 12 yrs.)

NAVIGATION: NAVIGATION: NECESSARY FOR OVERSEAS TRADENECESSARY FOR OVERSEAS TRADE

Off we go into the Off we go into the sunset, hopefully sunset, hopefully

knowing where we knowing where we are goingare going

Sextant•Measures the angle between the horizon & the sun when the sun is at its highest point (noon)

•Tables show which line of latitude the sun should be above on that day

•Ex: Noon on 21 December (Sun directly overhead)

•On 21 Dec. sun is above Tropic of Capricorn

• Latitude = 23.5 ° S.

The arm is positioned so the sun reflects off mirror B & off mirror A (& eyepiece)

What you see: sun superimposed on horizon

Angle between sun & horizon is read off the scale, compared with tables•The sextant uses 2 mirrors: (1) Mirror A – horizon(2) Mirror B – sunlight reflects off (attached to a movable arm)

GREENWICH, ENGLANDGREENWICH, ENGLANDHOME OF THE PRIME MERIDIAN & GREENWICH MEAN HOME OF THE PRIME MERIDIAN & GREENWICH MEAN

TIMETIME•Royal Observatory in Greenwich England Royal Observatory in Greenwich England

•Founded (1675) by King Charles IIFounded (1675) by King Charles II

•Built to solve Built to solve Longitude Problem Longitude Problem (finding east-west (finding east-west position) at sea & out of sight of landposition) at sea & out of sight of land

•Greenwich Time Ball (1833):Greenwich Time Ball (1833):

•1 of world's 11 of world's 1stst visual time signals visual time signals

•Ball drops daily at 1300: used to Ball drops daily at 1300: used to check marine chronometerscheck marine chronometers

•Can be seen from the Thames: Can be seen from the Thames: sailors know exact timesailors know exact time

•RO is now a center for astronomyRO is now a center for astronomy