Navigation

• Navigation is the science of directing the movements of a vessel from one place to another in a safe and efficient manner.

• In this course we will deal only with that part of navigation known as piloting and dead reckoning. Most advanced forms of navigation, including electronic and celestial methods, are based on the principles of piloting.

In This Lesson

• Types Of Navigation• Terms To Know• Charts and Symbols• Position by Latitude and Longitude• Plotting Course• Measuring Distance• Triangulation of Position• Determining Speed, Time Or Distance

Types of Navigation• Dead reckoning (DR)

– Determines position by advancing a known position for courses and distances.• Piloting

– Involves navigating in restricted waters with frequent determination of position relative to geographic and hydrographical features.

• Celestial navigation– involves reducing celestial measurements to lines of position using tables,

spherical trigonometry, and almanacs.• Radio navigation

– Uses radio waves to determine position by either radio direction finding systems• Radar navigation

– uses radar to determine the distance from or bearing of objects whose position is known.

• Satellite navigation– Uses artificial earth satellites for determination of position.

Terms To Know• Speed (S) is rate of motion, or distance per unit of time.• Knot (kn.), the unit of speed commonly used in navigation,is a rate of 1

nautical mile per hour. The expression • Speed of Advance (SOA) is used to indicate the speed to be made along

the intended track. • Speed over the ground (SOG) is the actual speed of the vessel over the

surface of the earth at any given time.• Course (C, Cn) is the horizontal direction in which a vessel is steered or

intended to be steered, expressed as angular distance from north clockwise through 360°.

• Heading (Hdg., SH) is the direction in which a vessel is pointed, expressed as angular distance from 000° clockwise through 360°.

• Direction is the position of one point relative to another.• Track (TR) is the intended horizontal direction of travel with respect to the

earth.• Coordinates, termed latitude and longitude, can define any position on

earth.

Label This Diagram In Your Notes

• Charts are graphic representations of areas of the earth for use in marine or air navigation. Nautical charts depict features of particular interest to the marine navigator.

• A nautical chart represents part of the spherical earth on a plane surface. It shows water depth, the shoreline of adjacent land, topographic features, aids to navigation, and other navigational information.

• It is a work area on which the navigator plots courses, ascertains positions, and views the relationship of the ship to the surrounding area. It assists the navigator in avoiding dangers and arriving safely at his destination.

To precisely locate points on the earth's surface, degrees longitude and latitude have been divided into minutes (') and seconds (").

For example, the U.S. Capitol is located at 38°53'23"N , 77°00'27"W

Determining Latitude and longitude Is a lot like playing a game of Battleship. By finding the horizontal and vertical axis on the grid.

074° 053’ 023 N 077° 021’ 055’ W

Very Precise, Not necessary for any of our work

070° 047 042 042° 034 038

042° 034 038 N

070 ° 047 042 W

Practice

X = 072° 018’ 000’ N 042° 031’ 000’ W

N = 072° 019’ 000’ N 042° 043’ 000 W

O = 072° 019’ 000’ N 042° 033’ 000 W

Using your chart of Manchester (KAPP 2073) Determine the Coordinates for:

1)West Manchester

2)The Observation Tower at Smith Point

042 ° 034’ 000’ N 070° 047’ 000’ W

042 ° 033’ 670’ N 070° 046’ 417’ W

Bouys and Markers

Observation Towers

Building

Depth

Boundary Lines

Compass Rose

Markers and Bouys

Buildings

Depth Markings

Boundaries

Identify the following features

Practice

• Plotting is drawing a vessels course on a chart. The tools to do this vary with the size of the vessel and the amount of charting space available.

• Dead reckoning determines position by advancing a known position for courses and distances

• Direction on a chart is measured from 000° to 360° in a clockwise direction from true north. (True north is the direction to the geographic north pole.)

• Labelling a Course Direction

• A course plotted on a chart is of little value when navigating unless you label its direction on the course line. Then the skipper need only refer to the chart for the course directions previously plotted. It is important to follow closely a standard method of labelling course lines. Do so, and anyone with basic skills can pick up your chart and understand and continue the work you’ve begun.

• The basic rule is: Label a course line for direction on and above the line, as near as practicable to the start of the course.

• A course label always starts with the letter “C” for “Course.” Always use three digits to the nearest whole degree, for example 005, 015, or 150.

• The degree sign is not used when labelling course, C instead is used.

090

270

180

000

080 070 060050

040

030

020010

000

260 250 240 230220

210

209190

180

100

110

120

130

140

150

160

170

180

280

290

300

310

320

330

340

350

360

170 160 150 140130350 340 330 320 310

190

200

210

220

230

010

020

030

040

050

C 224

PracticeC 0

57

C 326 Using your Manchester Harbour Chart

Plot a course between these 3 waypoints

Distance

200

200

200

+

= 400

PracticeC 0

57

C 326 Using your Manchester Harbour Chart

Measure the distance of the course you made prior

0.42 Nm Approx

850 Yards

• Triangulation is determining your position by knowing the bearings of 3 objects in view and on the chart.

• To Triangulate you would need a compass, Azimuths ring or some other way to take bearings off your ship.

If you look out from your boat and see the 1 Bouy right ahead of you, you know you are somewhere on that red line

Looking directly to your left you see the river opening.

You are at the intersection

???147°

90°

178°

PracticeC 326 Using your Manchester Harbour

Chart Practice Triangulation If:

The building at Gales Pt is 129° to you

The building on the point near Black Cove is 353 ° to you

The red bouy off glass head is 075 ° to you

Calculations

Distance = S x T

(distance traveled)

(average actual speed)

(elapsed time)

60

T

S

Speed = 60 x D

Time = 60 x D

• Your vessel is anchored at 48°41 N 123°29 2 W

• Set a course for a point 0.5Nm E of Patey Rock

• Once in position change direction and make a new course of 068° towards Chad Island

• Follow this course for exactly 3Nm

•Make a starboard turn and set a course for a point located exactly between U14 and U12

•Record the depth at this position (39m)

• Set a course for Imrie Island and record this in the ships log (108°)

• Approximately .3Nm N 1.4 Nm E from Imrie Island lies Pt Fairfax – Anchor your vessel 100m E of FI(3)

• Log your depth at this position

• After finishing lunch you go up to fix your position and find you have moved. You determine that – Turn Point is located at 146° relative to your position– FI(3) at Pt. FairFax is 226° relative to your position

• Log your new position and depth in the ships log (123° 016 W 048° 043 002 N)

• Log the distance you have dragged anchor (1.7Nm approx)

• Make a course of 172° for 3.2Nm

• You spot a flare 122° from your position, roughly 3Nm out (danger shore 3.2Nm at 122°) Report this to the CG on VHF 16 and standby

• AUDIO message (CG located at sidney island) determine time to respond and log it