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Newcastle Yacht Club Navigation Info Session Saturday, January 29, 2011 Bart Bies Brian Brennan Harvey Ostrander. Introduction. Welcome Introductions Washrooms Formal Presentation Break Real World Examples Informal Questions and Answers Hopefully go for 3 hours (to 4pm). Agenda.
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Newcastle Yacht ClubNavigation Info SessionSaturday, January 29, 2011Bart BiesBrian BrennanHarvey Ostrander
Introduction • Welcome • Introductions • Washrooms • Formal Presentation • Break • Real World Examples • Informal Questions and Answers • Hopefully go for 3 hours (to 4pm)
Agenda • Navigation Theory • Navigation Tools • Skills • Reading Lat/Long from chart • Plotting a course • Ded Reckoning • Fixing a position • Calculating Distance, Speed, and Time • Real Word Examples: • Sail Boat leaving Newcastle for Cobourg • Power Boat leaving Cobourg • Course to avoid Peter’s Rock • Sail Boat leaving Cobourg • Determining when to tack
Latitude • Angular distance from the equator • Place on earth North or South of the equator • Equator is 0°, North Pole is 90° • First part of a co-ordinate (LA before LO) • Lines of latitude form a circle parallel to the equator • May have heard of the 49th Parallel
Longitude • Angular distance from the prime meridian • Place on earth East or West of the prime meridian • 0° to 180° eastward and 180° westward • Second part of a co-ordinate (LO after LA) • Lines of longitude are closer together near the poles • May have heard of the100th meridian“Where the great plains begin”
Co-Ordinates • Where you are anyplace on earth • Expressed in latitude and longitude • LA before LO (latitude before longitude) • Degrees, minutes, seconds • one degree can be divided into 60 minutes (') • one minute can be divided into 60 seconds (“) • Also 10ths of a second • Newcastle Pier is at: N 43° 53’ 66.0” W 78° 34’ 54.6” N 43° 53.66’ W 78° 34.55’ N 43 5366 W 78 3455 N 43 53.660 W 78 34.546
Nautical Mile • One Nautical Mile = 1.15 statute miles = 1.85 km • How did they arrive at this? • The earth at the equator is approximately 25,000 statute miles round • Earth is measured in 360 degrees • Or 360 x 60 = 21,600 minutes • Divide circumference by number of minutes • 25,000 / 21,600 = 1.15 • Distance equal to one minute of latitude • If you have two positions on the same degree longitude and different latitudes • Take the difference and convert to minutes • You have the distance apart in nautical miles • Q: What is the distance between two lines of latitude (one degree/60 minutes)? • Q: How far south are we from the 49th parallel?
KNOTS • Speed through water • Boat moving through the water at a speed on ONE NAUTICAL MILE PER HOURis said to be moving at a speed on ONE KNOT • Boat moving at a speed of 10 NAUTICAL MILES PER HOURis said to move at a speed of 10 KNOTS • Don’t say 10 KNOTS per hour
Magnetic Compass • Points to Magnetic North Pole • Different than the geographic pole that the earth rotates on. • All charts use the True North Pole • Magnetic North Pole moves slightly with time
Correcting Compass Errors • Must convert Compass direction to True, as chart is done in True (and vice versa) • Variation is the failure of the compass to point to true north • is read from the compass rose on the chart • is the same for all boats in the same area • is the same for all directions in the same area • For our exercises, use variation of 12° W • Deviation is the failure of the compass to point to magnetic north • is caused by local magnetic fields on the boat. • is specific to an individual boat • changes with the boats heading • is read from the Deviation Table on the boat. • is effectively ZERO if using a hand bearing compass away from magnetic interference • For our exercises, use deviation of ZERO • NOTE: You can also configure your instruments to display True bearings
Compass Rose • True bearing on chart • Shows magnetic variation from True • Magnetic variation from year to year • Used to plot a course • For our exercises, use the compass rose closest to Cobourg: • 11°W in 1989 • Annual increase of 4’W • 22 years x 4’ = 88 minutes • Which gives us 12.28°W variation • Therefore, use 12°W for all compass variation calculations
Converting Compass Readings • T)ele V)ision M)akes D)ull C)hildren add W)onder • T)rue V)irgins M)ake D)ull C)ompany • Examples: • 192C • 000C • 108T
TVMDC Execises • See Information Sheet handouts
Tools of Navigation • What about marine electronics? • GPS Chartplotter Loran Radar • Need backup • Hard to plan course with GPS • Charting Tools • Charts • Pencils and Sharpener • Erasers • Rulers • Dividers • Magnifying glass • Log Book or pad of paper • A direction seeking device (compass) • A means of sighting and measuring angles • An accurate means of measuring speed • An accurate timepiece
Charts • No vessel should be on the water without some form of charts on board • Various commercial publications • Strip charts/ Ports book/Richardsons • Paper Charts • Large stiff paper (rolled or folded) • Chart Title Block • Shows region, scale, units of depth • Bottom left will have date of issue/update • You are responsibility to update them from NOTICE TO MARINERS from Canadian Coast Guard • Changes and additions to the chart • Changes to buoys • New Obstructions • Discontinuation of lights or fog signals • Done online with Canadian Coast Guard • Provided practice charts are photocopies from Rickardsons
Reading Co-ordinates • From point use ruler to move to scales on edges of the chart • left/right for latitude • top/bottom for longitude • From the provided chart, read the co-ordinates of the following: • Port of Newcastle light house • Westleyville stack • Port Hope harbour entrance • Cobourg harbour entrance • On the chart provided, identify the following from co-ordinates: • N43 51.032 W78 43.737 • N43 56.090 W78 13.813
Reading Distances • Use dividers • Always read distances from the lattitude (side) of the chart. • From the provided chart, calculate the distances from: • Newcastle to Port Darlington • Oshawa buoy to SW corner of Darlington exclusion zone • Port Hope to Peter’s Rock buoy • Peter’s Rock buoy to Cobourg harbour entrance
Plotting a Course • Boat leaves Newcastle heading south at 4 KNOTS at 10am • Compass Bearing 192 • Must calculate compass variation and deviation for True bearing • Draw a circle at your starting point • Record time below circle • This is called a FIX • Draw course line • Walk with Rulers from compass rose (or calculate angle with protractor) • Put True bearing above line • Put Speed in knots below line
Deduced Reckoning • Ded Reckoning is an estimate of where you are based on • Previously known position (FIX) • Speed/Course/Time • Indicated with a half circle on course line • Put time (HHMM) below it • From the previous example, how far out will you be in: • One hour • Two hours
Fixing a Position • Need two or more lines of position (LOP) • Should be 120° apart. • Done with handheld bearing device • Must convert bearing to True • Example:You have sailed for several hours from Newcastle and you take the following bearings: • Newcastle light house 042C • Darlington light house 322C • St Mary’s Cement pier 302C • Where are you? • Latitude/Longitude? • What depth of water should you be in • How far from Newcastle are you?
Calulating Distance and Time • Simple algebra • There are some slide rule tools to calculate this • Use a calculator • Speed in KNOTS • Distance in Nautical Miles • Time is in minutes • Examples • Distance 12 nm and taken 10 hours, what was your speed? • Distance 50 nm average speed was 6 KNOTS, how long it take you? • 4.5 KNOTS speed for 12 ½ hours, how far have you gone?
LOG Sheet • Sheet or pad of paper • Jot down events as they happen or as situations/conditions change • Can be transferred to a log book later
Example: Newcastle to Cobourg (Bart) • Sailing Vessel leaves Newcastle under sail at 1000 with wind from N (beam reach) • Course 120 for 2 hours @ 3 knots • What is your estimated position (latitude/longitude)? • What depth of water should you be in (feet/fathoms)? • How many nautical miles are you from Cobourg? • What course should you take? • What is your ETA? • Change Course to this new bearing and you find your speed increased to 6 knots • What is your new ETA? • When Port Hope if off your beam, you take three bearings • Port Hope 320C • Westleyville stack 106C • Radio Tower 186 ft tall 057C • Fix a position using these three bearings; are you close to your course? • How far from the Port Hope harbour entrance are you? • Are you going to clear Peter’s Rock?
Example: Powerboat Cobourg to Newcastle (Harvey) • Powerboat leaves Cobourg at 1000 • What compass course should you take to avoid Peter’s Rock? • You want to avoid the buoy by 500M to the south • After clearing Peter’s Rock, you change course to 243 • What is your ETA to Newcastle? • You really need to get back, so you increase speed to 12 knots • You hit something under the water, shearing your prop off • You determine you aren’t sinking, so you take some bearings: • Westleyville stack 062C • Newcastle light house 284C …before calling the coast guard for assistance • What is your position (latitude/longitude) • How far off shore are you? • What depth of water should you be in?
Example: Sailboat Cobourg to Newcastle (Brian) • SV Moonlight Hismiztress • Can point 45 degress to the wind • Can tack through 90 degrees • Leaves Cobourg at 1000 close hauled compass bearing 192 at 4 KNOTS • If she tacks right away, will she clear Peter’s Rock? • After 30/60/90 minutes, plot estimated positions, along bearing 192 at 4 KNOTS • If she tacks, will she clear Peter’s Rock, or make it to Newcastle on one tack? • What is the ETA to Newcastle for each case?
Example: Real World GPS Track • SV Still Time Leaves Cobourg on May 30, 2010 • Heads due south to try and make Newcastle in one tack • What happened here?
Bart Biesbart@bies.net (905)626-9447 www. capgemini.com