ELEMENTARY NAVIGATION

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1 ELEMENTARY NAVIGATION Chart Aus191 WGS84 MARINE RESCUE NEW SOUTH WALES Elementary navigation Registered Training Organisation Version 2.0

2 Acknowledgements This Elementary navigation Learner s Manual was created by MR KIOLOA volunteer, Wido Melis (TAE40110 Cert IV in Training and Assessment, TDM30101 Cert III in Transport and Distribution (Maritime Operations), for Marine Rescue NSW (MRNSW). o Elementary navigation is no n ion re o nise competency i is re ire no e e or marine search and rescue personnel/volunteers. Special thanks to Professor Harwood who kindly allowed the use of his diagrams (Figs. 1.1, ) and the exercise Determining co-ordinates. (Page 11) Further references are listed at the end of this manual. Version Control The information in this Learner s Manual is periodically updated. Trainers and Assessors must ensure they use the most recent version available in OTTER. [V2.0 n r 201 ] D isclaimer Although every effort has been made to ensure that the information is accurate at the time of publication, Marine Rescue NSW (MRNSW) disclaims all responsibility and liability (including without limitation and liability in negligence) for all expenses, damages and costs you may incur as a result of the information contained in this manual being inaccurate or incomplete in any way, or for any other reason. Copyright Enquiries related to this publication should be addressed to: State Training Manager Marine Rescue NSW Headquarters 202 Nicholson Parade Cronulla NSW 2230 PO Box 579 Cronulla 2230 P: E: training@marinerescuensw.com.au W: MRNSW Page 2 of 30

3 Contents Competency unit 5 Training overview 5 Introduction 5 Pre-requisites 5 Use a navigation chart Depth and height Degrees, minutes and seconds Direction/bearing Latitude Longitude Position/co-ordinates Mercator projection Determining co-ordinates (Latitude & Longitude) Distance and speed Plotting instruments Chart information Symbols and abbreviations 14 Navigation lights and shapes Lateral marks Cardinal marks Isolated danger and special marks Other aids to safe navigation Lights and shapes by vessels 20 Time/speed/distance calculations 22 Obtain tidal information Tide tables Tide characteristics Draught Determine depths 24 MRNSW Page 3 of 30

4 Determining a vessel s position Fixing position CTS to intercept (rendezvous) another vessel Global Positioning System (GPS) 28 References 29 MRNSW Page 4 of 30

5 Learning Outcomes At the completion of this unit, you will be able to use navigation charts, recognise navigation lights, accurately complete time/speed/distance calculations, obtain tidal information and determine a vessel s position. Competency unit SRBNAV001B - Elementary navigation It was determined that some competency units required for marine rescue did not exist so the State Rescue Board (SRB) has created some until such time they can be added to the National Training Package. Training overview The delivery plan provided shows an overview of the training involvement. The dates, time and locations will be mutually agreed to as the training progresses. Introduction Most search and rescue operations commence with the Marine Radio Operator, and operators need to have sufficient skills and knowledge of navigation in order to be able to track vessels and provide correct assistance to sea farers. The contents of this unit is not comprehensive enough to be suited for marine navigators, however; it is the basis of all navigation and will assist in the learning process of more advanced navigation competencies. Pre-requisites Induction MRNSW Page 5 of 30

6 Use a navigation chart Navigation: Determining a position and course on the Earth s surface With the space age, we can now include the Universe. 1.1 Depth and height Metrication has affected many changes in our lives but little effect in maritime operations. The only changes are in depth shown on charts (fathoms, a depth of 6 feet, have changed to metres) and heights (feet have also changed to metres). There are still charts current using fathoms and feet. 1.2 Degrees, minutes and seconds The main measure in navigation is an angular measure. Let s refresh our memories: (Fig. 1.1) a circle consists of 360 degrees (360 ) 1 = 60 minutes (60') 1' = 60 seconds (60") Figure 1.1 Don t confuse these minutes and seconds with measurement of time. MRNSW Page 6 of 30

7 1.3 Direction/bearing N For a directional system we need a reference/starting point. If we use the North Pole (N) as a reference point and imagine that we are standing at the centre of the circle, we can then measure the angle from North to another position on the face of the Earth. This angle is called a bearing. b (Fig. 1.2) Figure 1.2 If we look at a bearing of 180 we are looking towards the South Pole (S). At a bearing of 90 (090 ) we are looking East (E), at a bearing of 270 we are looking West (W) and the bearing to North (N) as the reference point is 000 (360 ). The four points N, E, S & W are known as Cardinal points. (Fig. 1.3) Variation: The Earth has a magnetic field and the positions of the North and South magnetic poles are not the same as the North and South geographical poles. Magnetic compasses point to Magnetic North but charts are oriented to True North. The difference between compass bearings and true bearings is called variation. The compass rose on a chart indicates the amount and direction of variation plus the annual change. Compass conversions: Because of the difference between compass and true north it is necessary to convert one to the other. To help determine whether to add or subtract a variation from True to Compass remember: Error East Compass Least (subtract) Error West _ Compass Best (add) MRNSW Page 7 of 30

8 1.4 Latitude The line formed on the Earth s surface where a plane that bisects the earth midway between the two poles is called the Equator. All lines on the earth s surface which run parallel to the Equator are called parallels of latitude or simply, Parallels or Latitude. (Fig. 1.3) Two lines of latitude will never intersect or cross and the distance between the lines will always remain constant. Latitude is measured by the angle at the Earth s centre between the place in question and the Equator. (Fig. 1.4) Latitude is therefore between 0 and 90 north or south (the Equator being 0 ) and only the Equator, 0, does not have a north (N) or south (S) direction. Figure 1.3 Figure 1.4 MRNSW Page 8 of 30

1.5 Longitude Great Circles are defined as any circle on the surface of a sphere, especially when the sphere represents the Earth, formed by the intersection of the surface with a plane passing

They cut the Equator at all parallels of latitude at 90. Unlike measurements of latitude, there is no natural reference point. The reference meridian selected is called the prime meridian.

9 1.5 Longitude Great Circles are defined as any circle on the surface of a sphere, especially when the sphere represents the Earth, formed by the intersection of the surface with a plane passing through the centre of the sphere. (Fig. 1.5) All lines of longitude are great circles, as well as the Equator, which is a line of latitude. (Fig. 1.6) Circles on the Earth s surface which run through both poles are called meridians. They cut the Equator at all parallels of latitude at 90. Unlike measurements of latitude, there is no natural reference point. The reference meridian selected is called the prime meridian. The prime meridian passes through the old observatory at Greenwich, near London UK. Greenwich is the internationally accepted prime meridian in most cases. All other meridians are named east (E) or west (W), from 0 to 180, depending on the angle at the earth s centre between the prime meridian and the one in question. (Fig. 1.7) Figure 1.5 Figure 1.6 Figure 1.8 Figure 1.7 MRNSW Page 9 of 30

Longitude. Remember that maximum latitude is only 90 and longitude 18

10 1.6 Position/co-ordinates A position on the Earth s surface is expressed in latitude + longitude known as co-ordinates. In other words; where a parallel of latitude and a meridian of longitude cross on the Earth s surface Example: " S " E or S E State/write Latitude first then Longitude. Remember that maximum latitude is only 90 and longitude Mercator projection Chart-makers had a problem developing charts of the world round. (Fig. 1.8) considering that it is In 1568 a mathematician, Gerhardus Mercator, solved this problem to some extend by developing a projection of the World on a flat piece of paper. Charts using the Mercator projection, known as, Mercator Charts do have distortions of Land Mass sizes unless they are near the Equator. (Fig. 1.9) Mercator s projection was exactly what sailors needed, shapes & directions. They were very willing to accept the size distortion. Figure 1.8 Figure 1.9 A straight line on a Mercator Chart is called a Rhumb line. MRNSW Page 10 of 30

The red dot in diagram b would have a designation of 30 N 60 E a. b. Determine the co-ordinates of the locations on the map below.

11 1.8 Determining co-ordinates (Latitude & Longitude) The diagram a shows a globe with the latitude and longitude lines on it. The Equator and Prime Meridian have been highlighted in red. The location at the point where these two lines meet would be designated as Latitude 0 Longitude 0. The red dot in diagram b would have a designation of 30 N 60 E a. b. Determine the co-ordinates of the locations on the map below. Enter your answers in the spaces provided below. (Latitude and Longitude must be entered with a single space between the degrees and the N, S, E or W) Example: "10 W". The N, S, E and W must be entered as a capital letter. A C E B D F MRNSW Page 11 of 30

1.9 Distance and speed The nautical mile (n mile or M) also known as a Sea Mile (1852 m at the Equator) is the basic measure of distance in all aspects of navigation and a Cable (approx.

12 1.9 Distance and speed The nautical mile (n mile or M) also known as a Sea Mile (1852 m at the Equator) is the basic measure of distance in all aspects of navigation and a Cable (approx. 200 yards) is one-tenth of a nautical mile. A nautical mile is the distance on the Earth s surface subtended by one minute (1') of latitude. Therefore there are 60 M in one degree. The Latitude scale is the left and right (top to bottom) scale on a chart. Always use the Latitude scale opposite the area of operation to measure distance. (Fig. 1.10) Never use the Longitude scale to measure distance. A knot is a speed of one nautical mile per hour. Figure 1.10 MRNSW Page 12 of 30

1.10 Plotting instruments a. Pencil: 2B b. Eraser: soft white rubber a. b. c. c. Drawing compass: long legged d. Dividers: long legged e. Protractor f. Parallel Ruler d. e. f. Take care of charts and plotting instruments!

13 1.10 Plotting instruments a. Pencil: 2B b. Eraser: soft white rubber a. b. c. c. Drawing compass: long legged d. Dividers: long legged e. Protractor f. Parallel Ruler d. e. f. Take care of charts and plotting instruments! 1.11 Chart information Chart number: identified by alpha-numerical catalogue numbers Australian charts start with AUS (Refer cover) Printing date: upper right margin Water depth: soundings and contours Dimensions: lower right margin in brackets Title: where it doesn t obscure essential navigational information. Usually includes: Area shown Survey date Sounding units (Metres or Fathoms) Natural scale Notes on heights Projection (i.e. Mercator) Caution notes: often found under the title but may appear elsewhere Tidal information: with the caution notes Publication: centre bottom margin (may include new edition & large corrections) Small corrections: lower left margin Notices to Mariners are shown MRNSW Page 13 of 30

14 1.12 Symbols and abbreviations Lines and symbols used on charts are contained in the publication, CHART 5011 (Fig. 1.11) Figure 1.11 MRNSW Page 14 of 30

Navigation lights and shapes Navigation lights are required to be shown or be available to be shown by all vessels between sunset and sunrise & when

1 Lateral marks Marks are used to show well established channels indicating the port (left) and starboard (right) hand side of channels The coming in

1 Entering harbours or travelling upstream in a river, leave port hand marks on your port side and starboard hand marks on your starboard side.

Lateral marks are not always placed in pairs. When you see just one, you will need to bear in mind the upstream-downstream rule.

15 Navigation lights and shapes Navigation lights are required to be shown or be available to be shown by all vessels between sunset and sunrise & when visibility is restricted. Buoys and beacons (marks) are positioned in our waterways to direct vessels clear of hazards and assist with safe navigation. 2.1 Lateral marks Marks are used to show well established channels indicating the port (left) and starboard (right) hand side of channels The coming in going out rule! (Fig. 2.1) Figure 2.1 Entering harbours or travelling upstream in a river, leave port hand marks on your port side and starboard hand marks on your starboard side. Leaving harbours or travelling downstream the opposite applies. There s some red, port, left in the bottle travelling upstream. Lateral marks are not always placed in pairs. When you see just one, you will need to bear in mind the upstream-downstream rule. The Port Mark is coloured red and has the basic top shape of a can. At night it shows a red light and flashes to one of four sequences. (Fig. 2.2) The Starboard Mark is coloured green and has the basic conical top shape. At night it shows a green light flashes to one of four sequences. (Fig. 2.3) Figure 2.2 Figure 2.3 MRNSW Page 15 of 30

16 2.2 Cardinal marks Cardinal marks get their name from the cardinal points of a compass. (Refer page 7) They indicate the direction of clear water (for example, if a mark reads north then the safe passage is on the northern side of the buoy. Figure 2.4 (Below) shows the day shapes and colours and the sequence of white flashing light for each cardinal mark at night. The sequence of flashes are based on an analogue clock with N being 12 O clock etc. Figure 2.4 Marks are not always lit. (Refer page 20) MRNSW Page 16 of 30

2.3 Isolated danger and special marks An isolated danger mark shows isolated danger (for example, rocks, reef, wreck or shoal) with

The day shape of the isolated danger mark is two black spheres on top of a pillar or spar coloured black over red (like the red bellied

Steer to clear by a good, safe margin! Figure 2.5 The opposite of a danger mark is the safe water mark. (Fig. 2.6) Figure 2.

17 2.3 Isolated danger and special marks An isolated danger mark shows isolated danger (for example, rocks, reef, wreck or shoal) with good water all around. The day shape of the isolated danger mark is two black spheres on top of a pillar or spar coloured black over red (like the red bellied black snake). Light, when fitted, is white flashing in a group of two. (Fig. 2.5) Do NOT approach this mark closely. Steer to clear by a good, safe margin! Figure 2.5 The opposite of a danger mark is the safe water mark. (Fig. 2.6) Figure 2.6 A special mark does not have a specific meaning or use. They can be used as lateral markers using can or conical shapes (for example when indicating temporary danger like a sunken vessel. When fitted, it flashes a yellow light at night. (Fig. 2.7) Figure 2.7 MRNSW Page 17 of 30

18 MRNSW Page 18 of 30

2.4 Other aids to safe navigation Although not part of the International Association of Lighthouse Authorities (IALA), other aids to safe navigation include: Leading beacons/lights (Leads) Leads vary

19 2.4 Other aids to safe navigation Although not part of the International Association of Lighthouse Authorities (IALA), other aids to safe navigation include: Leading beacons/lights (Leads) Leads vary in shape. They are commonly red triangular in shape with the front beacon s apex upward and the rear beacon inverted. Many new leads are rectangular in shape. Although not universal, fluorescent blue lights display the leads at night. (Ulladulla has red triangular leads but Batemans Bay has rectangular leads) (Fig. 2.8) In transit open Directional and sector lights Figure 2.8 A directional light may only be seen in a small arc. Its purpose is similar to leads. Sector lights normally display arcs of different lights to warn sailors of hazards and advise clear channels. (Fig. 2.9) Batemans Bay has white sector lights advising channels N & S of the Toll Gates. (See cover) Figure 2.9 A vessel is in safer when keeping beacons/lights in transit or a set bearing. MRNSW Page 19 of 30

20 2.5 Lights and shapes by vessels International Regulations for Preventing Collisions at Sea, 1972: Rules cover international definitions of lights and shapes to be displayed by vessels for preventing collisions at sea. There are also local signals we need to be aware of. Correct identification and interpretation of meaning of lights and shapes, displayed on vessels, is critical to avoiding collisions at sea. Lights on vessels may be a combination of: A. Masthead light - white B. All-round light - white C. Port /Green red/green D. Stern light white DY. Stern towing yellow Power Vessel (<12m) underway B. & C. Power Vessel (<50m) underway A. C. & D. Towing A. x 2 C. D. & DY Sailing vessel underway C. & D. Vessels (<12m) at anchor B. Vessels at anchor B. & B near stern Day shape recognition (Fig page 23) Light recognition (Fig page 23) Underway : not at anchor or made fast to shore or ground. Making way : moving through the water (by engine, oars or sail). MRNSW Page 20 of 30

21 Figure 2.10 Figure 2.11 MRNSW Page 21 of 30

22 Time/speed/distance calculations Speed at sea is measured in knots (nautical miles per hour). By understanding the relationship between time, speed and distance, it is possible to estimate how long it takes to reach a destination or use it to determine a vessels location. Distance on Earth s surface subtended by 1' latitude = 1 n mile (M) Speed of 1 n mile p/h = 1 knot Speed = Distance Time (hrs.) Time (hrs.) = Distance Speed Distance = Speed x Time The Speed, Time and Distance Triangle. (Fig. 2.12) DISTANCE SPEED X TIME hrs. Figure 2.12 Time must be in hours! (Example: 2 hrs 12 min = 2.2 hrs) MRNSW Page 22 of 30

Obtain tidal information Tides are the rise and fall of water due to gravitational pull of moon and sun. (The moon being closer exerts a greater pull).

Similarly, when they are at right angles to each other (half-moon), they work in different directions producing lower tides known as neap tides. 4.

23 Obtain tidal information Tides are the rise and fall of water due to gravitational pull of moon and sun. (The moon being closer exerts a greater pull). When the moon is in line with the sun (new moon & full moon), their combined gravitational pull creates bigger tides known as spring tides. Similarly, when they are at right angles to each other (half-moon), they work in different directions producing lower tides known as neap tides. 4.1 Tide tables Local tides are can generally be accurately predicted from analysis of long-term tidal records. The Australian Hydrographic Office (AHO) publishes local tides through the Bureau of Meteorology (BOM) NSW Maritime produces a free NSW tide predictions publication for the boating public or look at their website (Fig & Fig are samples from NSW Maritime s publication) i re 2. i re 2. Add 0ne hour when Daylight Saving Time is in force! MRNSW Page 23 of 30

24 4.2 Tide characteristics Duration The time taken for a tide to rise (flood tide) or fall (ebb tide) Range The difference between the height of a high and the height of a low tide (or visa-versa). Flow The rate per hour that a tide will rise or fall. 4.3 Draught The draught of a vessel is the distance from the waterline to its lowest part. 4.4 Determining depths To determine the actual depth at a location at a particular time, the calculated height of the tide must be added to the charted (datum) depth. Charts contain depth indicators. The chart datum is based on the lowest tide that could be theoretically predicted to occur under average meteorological conditions. (Fig page 27) One reasonably accurate method of calculating the height of the tide at a given time is the Rule of Twelfths. (Fig. 2.15) The Rule of Twelfths assumes that: In 1 st & 6 th hour the tide will move by 1/12 th of the tide range. In 2 nd & 5 th hour the tide will move by 2/12 th of the tide range. In 3 rd & 4 th hour the tide will move by 3/12 th of the tide range. 1/12th 2/12th 3/12th 3/12th 2/12th 1/12th 1 st h 2 nd h 3 rd h 4 th h 5 th h 6 th h 12/12th Approximately 6 hours Figure 2.15 If a tidal range is 6 m and is ebbing, the drop in water level over the 6 hours will be: 0.5 m after 1 hr, 1.5 m after 2 hrs, 3.0 m after 3 hrs, 4.5 m after 4 hrs, 5.5 m after 5 hrs. MRNSW Page 24 of 30

25 Figure 2.16 It is the master s/coxswain s responsibility to determine water depth! MRNSW Page 25 of 30

26 It is critical for Marine Search and Rescue members to accurately plot vessel positions on a chart and be able to determine the course to steer to intercept another vessel. When plotting a vessel s position, place a small circle over the position and label it with a four digit time and log the reading (Distance travelled & speed). 5.1 Fixing position Dead reckoning: expected position after sailing a certain course for a certain distance. This means that we continue to plot a vessel from its last known position. Transit fix: When two objects are lined up they are in transit. The vessel must be on the same extended line. Bearing fix: Plotting a bearing from a single known point, like a places the vessel somewhere on that bearing. Lighthouses and prominent known land features are excellent for taking a bearing fix. Plotting two or more such bearings will provide a true bearing fix for the vessel but the points should be at least 30 apart. On a single bearing a fix may be estimated by depth sounding. All chart plotting is done with True bearings. Although bearings should be relayed in True bearings, it is advisable to stipulate or ask if a bearing is True or Compass. MRNSW Page 26 of 30

27 5.2 CTS to intercept (rendezvous) another vessel To intercept a vessel that is sailing due 3 knots when you are 6 knots with vessels positions and times as shown, what course would you steer (CTS) and at what time would you intercept? Interception point at 1412 < Other vessel 3 at 1200 E B A 6 Your CTS C Your Pos n at 1200 D PROCEDURE: Plot then join initial positions of both vessels line AD Plot course & then the position of the other vessel after 1 hour s 3 knots point B With B as centre and your distance run in 1 6 knots as radius, describe arc to cut AD at C Join CB. (If you were at C, this would be your track to intercept the other vessel in 1 hour) But, since you are at D, plot DE parallel to BC. This is your course and distance to point of interception. (The ratio AB:BC is the same as AE:DE) Your course will be 328 and time of Interception = 1412 hours CAUTION: BC (not AC) = 6 miles MRNSW Page 27 of 30

28 5.3 Global Positioning System (GPS) GPS units are in common use but their limitations must be understood. They are a good aid to navigation but some of associated problems but not limited to this list are: The GPS units interpret signals from at least 3 satellite transmissions controlled by the USA. There have been times that for security reasons satellite transmissions have provided errors on purpose so that locations are not exact. Chart plotters in conjunction with a GPS unit may not be properly calibrated. Operators may not read or interpret GPS information correctly. Having completed the training, you are now able to: Use navigation charts Recognise navigation lights Accurately complete time /speed/distance calculations Obtain tidal information Determine a vessel s position Determine CTS to intercept another vessel MRNSW Page 28 of 30

29 References Fotosearch, Watertown Road, Waukesha, WI USA, viewed 12 March 2009, (Fig. 1.8) Gandy D., Captain, 1996, Australian Boating Manual, third edition. *Harwood R., Professor, Black Hawk College, th Ave. Moline, IL USA International Regulations for Preventing Collisions at Sea (IRPCS), viewed 29 March 2009, Media Monitors Network, viewed 12 March (Fig. 2.6) Northern Territory Transport Group, Marine Safety, the Northern Territory Safety Guide for Pleasure Craft, viewed 19 March (Figs. 2.2, 2.3, 2.5, 2.6 & 2.14) o s Maritime, NSW Tides , Tidal predictions for Sydney Harbour with moon phases July 2014 June (Figs & 2.14) Risk, Response & Rescue, RTO, 2007, Royal Volunteer Coastal patrol (RVCP) Marine Radio Operator- Learner guide. (Fig. 2.6) Wikipedia, the free encyclopedia, viewed 12 March (Fig. 2.4) MRNSW Page 29 of 30

30 Chart plotting terminology, labelling & symbols MRNSW RTO Elementary navigation V May 2013 Page 30 of 30

AUS small scale charts for coastal navigation. Scale: 1 to 150,000

AUS small scale charts for coastal navigation. Scale: 1 to 150,000 CHART-WORK SCALE Charts are available in different scales depending on their use. For passage planning you would use small scale charts and for close quarter manoeuvring you would use larger scale charts