Piloting Course (Inland Navigation) Chapter 3 Plotting and Planning Techniques SEO – Dave West Instructor – Art Mollica United States Power Squadrons ®

Slide 2 Any questions on homework from Chapter 2? 1.The most common chart used on the water is a: (d) mercator projection. WN-Ch 4, pg 24 2.On a mercator chart all line of: (a) latitude and longitude are straight lines and intersect at 90 º. WN-Ch 4, pg 24 3.A chart datum identifies, by letter and numbers, the: (c) coordinate systems. WN-Ch 2, pg 29 and SG-Ch 2, ¶ 8 4.Height of objects are indicated using as a reference: (a) mean high water (sometimes mean higher high water). WN-Ch 5, pg 58 5.A nautical chart shows detail of: (b) detail features both above and below the water. SG-Ch 2, ¶ 4 6.Large scale charts show a: (c) small area in great detail. WN-Ch 4, pgs The labels for charted beacons and buoys are: (d) beacons vertical, buoys slanted. SG-Ch 2 ¶ A lubber line is: (a) a fixed directional line on the compass. WN-Ch 4, pg 47 9.Variation is the angular distance between: (b) magnetic north and true north. SG-Ch 2, ¶

Slide Fill in the missing values in the following table. SG-Ch 2, pgs A fathom is: (b) 6 feet. SG-Ch 2, ¶ The starboard side of a channel when returning from sea is marked with: (d) red color – conical (num) – even numbers. SG-Ch 2, pg When entering from sea, a buoy marking the junction of two channels where the preferred course is to the left would be a _____ and would have a letter designation. (c) red over green (horizontal) nun SG-Ch 2, ¶ Measuring distance on a chart use the horizontal scale (longitude) at the top/bottom of the chart. (b) False WN-Ch 4, pg For a 3-D GPS fix you need: (d) four satellites. WN -Ch 4, pg GPS provides you with: (c) current position. WN-Ch 4, pg Depth sounders use a transducer to: (c) send acoustical sound downward through the water. Any questions on homework from Chapter 2? True347 º 122 º 062 º 237 º 004 º Variation11 º E13 º W5 º E14 º W10 º E Magnetic336 º 135 º 057 º 251 º 354 º

Slide 4 Basic Plotting Techniques  Dead Reckoning Estimated position using course steered and distance traveled  Distance determined by direct reading LOG or…  60D=ST formulas Determine position from prior FIX  Bearings Visually establish a position  2+ Bearings establish a fix Related techniques  Ranges  Relative Bearings  Seaman’s Eye TRIP (NM)

Slide 5 Accuracy of DR?  Helmsman Issues: Accuracy of Course Steered  Cannot wander Accuracy of Speed Reading  Difficult to obtain precise value Measurement of Time  Other factors: Currents & Winds Obstacles and other boats Fatigue

Slide 6 DR Plotting & Labeling  DR Plot Shows direction and speed of courses steered Shows position from DR calculations  DR Position Plotted  At every Course or Speed change  Time of bearing  Also nominally every hour Labeling  Dot for location, surrounded by half-circle  Time labeled on diagonal C 087 M S Initial Fix 1030

Slide 7 Methods of Taking Bearings  Hand-Bearing Compass Every boat should have one  Handy  Reasonably accurate  Easy to use  Good as backup compass  Sight across ship’s compass  Sight lines may be limited  Often less accurate  Bow bearing

Slide 8 Bearing Plotting & Labeling  A Bearing gives a Line of Position (LOP) You must be somewhere on that LOP Cannot tell precisely where  Based on direction of visible charted Landmarks Direction from boat to landmark Plotted towards landmark  Taken on the Water Plotted & labeled in real time Labeled  Time of LOP on top of line  Bearing (Magnetic) below line C 087 M S Initial Fix M 1030 No longer teach assumed position Somewhere on this line

Slide 9 How to maintain a DR plot. Using “Seaman’s Eye” to confirm DR positions. At 0945, depart G “1” Fl G 2s Oyster River on a true course of 075º. Speed is 6.5kn. At 1010, you change to a magnetic course of 355º. At 1030, you increase speed to 8.5kn. At 1105, you take up a true course of 090º. What is a visual check on the 1030 DR position? What is your sounding at the 1105 DR position? 0945 C 090M S 6.5 C 355M S C 355M S C 105M S 8.5 Exercise 3-1 T = 075 V = +15W M = 090 D = (ST)/60 D = (6.5x25)/60 D = 2.7nm M = 355 V = -15W T = 340 D = (ST)/60 D = (6.5x20)/60 D = 2.2nm D = (ST)/60 D = (8.5x35)/60 D = 5.0nm T = 090 V = +15W M = 105

Slide 10 Sight Bearing from Boat to Landmark M You are somewhere on this line but don’t know exactly where.

Slide 11 How to Plot a Bearing C 087 M S M 1030 MB = 035 V = -15W TB = 020

Slide 12 Exercise 3-2 Taking and plotting compass bearings. Plot and label the magnetic course, bearings and DR positions. At 1005, depart R “8” I Q R Main Channel on a true course of 080º Speed is 6.2kn. At 1035, using a hand bearing compass, you take a bearing of 185º on R “6” Fl R4s Main Channel. Using “Seaman’s Eye”, how can you verify this bearing? At 1110, you take a compass bearing of 355º on the Dutton’s Island light. What does this tell you about your speed? 1005 C 095M S M M 1110 T = 080 V = +15W M = 095 D = (ST)/60 D = (6.2x30)/60 D = 3.1nm MB = 185 V = -15W TB = 170 D = (ST)/60 D = (6.2x35)/60 D = 3.6nm MB = 355 V = -15W TB = 340

Slide 13 FIX’s from two Bearings  Two crossed Bearings give a FIX  Accuracy Determined by accuracy of each bearing Depends on angle between bearing  Too close, poor accuracy ( 150°)  90° = ideal (2 bearings) 90º 160º +/- 2 º Error Somewhere inside red area

Slide M 2 – Bearing FIX M Your FIX is at the intersection of the two LOP’s. 1035

Slide 15 Using two bearings to plot a fix. At 0900, depart RW “OR” Mo (A) Oyster River on a true course of 350º. Speed is 6.0kn. At 0936, you take a compass bearing of 285º on Chapman Point light and a compass bearing of 356º on the light house north of Shark River. At the 0936 fix, take up a magnetic course of 077º. Increase speed to 11.0kn. What are the L and Lo of the 0936 fix? Observe the 0936 DR and fix positions. What happened? Using “Seaman’s Eye”, what can you say about your 0936 fix? Exercise C 005M S 6.0 T = 350 V = +15W M = M M D = (ST)/60 D = 6.0x36/60 D = 3.6nm CB = 285 V = -15W TB = 270 CB = 356 V = -15W TB = M = 077 V = -15W T = 062 C 077M S º 41.4’N 72º 01.3’W 0936

Slide M M – Bearing FIX’s May not cross at a single point. Position nominally at center of triangle M

MINUTE BREAK PLEASE TAKE YOUR SEATS

Slide 18 Relative Bearings  Bearings using the Boat as reference  Used occasionally  Need obvious reference points on boat Bow Bearings Beam Bearings  Falls into category of “Seaman’s Eye” Not precise, but good check  Change in Relative Bearing useful for determining possibility of collision

Slide 19 Bow Bearing 240M

Slide 20 90º Beam Bearing C 153M Starboard Beam Bearing MH = 153º RB = 090º MB = 243º 270º Port Beam Bearing MH = 153º RB = 270º MB = 063º 243M 063M

Slide 21 Using “Seaman’s Eye” to take bow and beam relative bearings. At 1000, depart RW “OR’ Mo (A) on a true course of 349º. Speed is 6.0kn. At 1019, you take a starboard beam bearing by “Seaman’s Eye” on R “10” Q R Main Channel. At 1100, you briefly turn the bow toward Fl R 6s 40ft 10M HORN north of Shark River and take a bow bearing of 344ºM, and notice that the light on Chapman’s Point is exactly off your port beam. Plot the 1100 fix and steer a new course of 105ºM. At 1147, you take a port beam bearing on the tower with a red light to the north. Exercise C 004M S 6.0 T = 349 V = +15W M = M M D = (ST)/60 D = 6.0x19/60 D = 1.9nm RB = 090 MH = 004 MB = 094 V =-15W TB = D= (ST)/60 D=(6.0x41)/60 D= 4.1nm M RB = 000 MH = 344 MB = 344 V = -15W TB = RB = 270 MH = 344 MB = 254 V = -15W TB = 239 M = 105 V = -15W T = 090 C 105M S 6.0 D = (ST) / 60 D=(6.0x47)/60 D = 4.7nm 1147 RB = 270 MH = 105 MB = 375 V =-15W TB = M

Slide 22 Ranges  A Range is a bearing using Two visible charted landmarks or Navigation aids  Provides a visual cue on the water to staying on course  Uses Navigation in narrow channels Alignment with Harbors Can build own to help navigate  Very Precise

© 2004, “The Weekend Navigator” Slide 23 Formal Range

Slide 24 Outside Range

© 2004, “The Weekend Navigator” Slide 25 Informal Range

Slide 26 Select and measure ranges from any two charted landmarks. Create a range to the entrance of Perkins Cove, approaching it from the North on a magnetic course of approximately 200º. Assume that the tower on the west side of Perkins Cove is illuminated and its height to be 40ft. Plot the range and create a turn into Perkins Cove Exercise 3-5 – Ranges T = 184 V = 015W M = 199 Range 199M T = 156 V = 015W M = 171 C 171M

Slide 27 Using GPS to Navigate  GPS gives you your position – precisely and continuously  But, how do you navigate and stay safe?  Must periodically plot position on a chart Essential to have reference to what is nearby Or, along your path Or, beneath you Can be a tedious task Best approach - Create pre-qualified legs on the water and Follow your plan

Slide 28 Characteristics of a Safe Path Clear of Obstacles and Sufficient Depth for boat 1) Draw ‘legs’ (paths) 2) Check for obstacles Shallow Water Rocks Wrecks Other Obstacles 3) Safe Path Width Nominally about 1/10 th nm on each side  Equal to smallest increment on latitude scale  About 600 feet Allows for helmsmanship, other boats, some drift

© 2004, “The Weekend Navigator” Slide 29 Minimum Path Width EDF WFBGC

Slide 30 Working Around Obstacles EDF WFBGC WFBSS XTE 0.4

Slide 31 Digital Charting CD  Coastal Explorer Viewer Software Plot marks, waypoints, routes Annotate charts (Raster) Upload, download to GPS Edit  Charts Bowditch Bay, 1210tr Chart set – Block Is to Martha’s Vineyard  Nautical, Topo, Photo, Aerial – selected Charts –  Small scale – Entire U.S. coasts, Great Lakes, Hawaii, Alaska, North Pacific, Caribbean areas, World

Slide 32 Coastal Explorer Viewer Supplementary aid to navigation, not a primary tool!

Slide 33 Coastal Explorer Viewer Title Bar Tab/Status Bar Tool Bar Chart Window Overview Properties Last thing in main chart you clicked on. Chart info ‘read only’ Mark, route bearing, range can be changed

Slide 34 Coastal Explorer Viewer Tools

Slide 35 Coastal Explorer Viewer Tools Chart Portfolio Install Charts Configure GPS Program Options Help & Support

Slide 36 Coastal Explorer Viewer Tools

Slide 37 Questions ? … Comments

Slide 38 Homework  Read Chapter 4 – Student Guide  Review Chapters 4 & 5 – Weekend Navigator  Do Chapter 3 homework  Next class – 14 February