Advanced Piloting Course (Coastal

Navigation)

Chapter 10

Review

Educational Officer – Dave Westdwest@voyager.net - 651-429-3840

Assistant Educational Officer – David Moberg

davidmoberg@att.net – 715-386-8582 Instructor – Art Mollica

artmollica@usfamily.net - 651-777-0277

United States Power Squadrons®

22APPENDIX A - WEEKEND CRUISE

PART 5

33

x

x

x x

x1101

M0

1106 GPS

x1151 GPS

C 129M S 7.0

1213

1228

1228

D 1.9

1228

D 1.9

1151 GPS

1300

C

02

0M

S

10

.0

1400

1420 GPS

Set 253M Dft 2.1

CO

G 0

09M

SO

G 8

.7

25) At 1400 you decide not to raft up with your friend. You leave “1” BELL at the entrance to Menemsha Basin and lay a course for BR C southwest of Lucas Shoal. Your speed is 10kn. Your GPS indicates a bearing of 020ºM. The wind has changed direction and is coming from the northeast and has increased in strength causing whitecaps in Vineyard Sound. You are having trouble holding the course. You suspect there is a current causing your boat to drift towards the southwest. At 1420 you can see the BR C to the northeast and you decide to stop and get a GPS Fix and calculate your set and drift. The 1420 GPS Fix position is L 41º24.3’N and Lo 70º46.7’W.

1420

WptPan

DBG29

VSRWNA

QKHG1

VSBR

MPG1

BBRR

SPRR2

44

x

x

x x

x1101

M0

1106 GPS

x1151 GPS

C 129M S 7.0

1213

1228

1228

D 1.9

1228

D 1.9

1151 GPS

1300

C

02

0M

S

10

.0

1400

1420 GPS

Set 253M Dft 2.1

CO

G 0

09M

SO

G 8

.7

25) At 1400 you decide not to raft up with your friend. You leave “1” BELL at the entrance to Menemsha Basin and lay a course for BR C southwest of Lucas Shoal. Your speed is 10kn. Your GPS indicates a bearing of 020ºM. The wind has changed direction and is coming from the northeast and has increased in strength causing whitecaps in Vineyard Sound. You are having trouble holding the course. You suspect there is a current causing your boat to drift towards the southwest. At 1420 you can see the BR C to the northeast and you decide to stop and get a GPS Fix and calculate your set and drift. The 1420 GPS Fix position is L 41º24.3’N and Lo 70º46.7’W.

1420

25a) Calculate the set and drift at 1420. 25b) Why is your drift more than calculated? 25c) What is your speed over ground? 25d) What is your course over ground?

VSBR

QKHG1

VSRWNA

DBG29

1

55

x

x

x x

x1101

M0

x1151 GPS

C 129M S 7.0

1213

1228

1228

D 1.9

1228

D 1.9

1151 GPS

1300

C

02

0M

S

10

.0

1400

1420 GPS

Set 253M Dft 2.1

CO

G 0

09M

SO

G 8

.7

1420C

0

18

M

S 1

0.0

XTE 0

.2

1435 GPS

1447 Visual

1447 Course T = 256ºW V = 015ºW M = 271º

26) You take another GPS fix at 1435 L 41º 24.2’ N and Lo 70º 47.0’ W and continue towards R “28” Fl R 4sec BELL from the 1435 fix. Using the GPS cross track error (XTE) feature you stay within 0.25nm of your course. When you arrive at buoy R “28” Fl R 4sec BELL at your planned time of 1447 you make a decision to go to Buzzards Bay through Quicks Hole. You continue on a course to the buoy south of Quicks Hole and arrive at G “1” Fl G 4sec BELL at 1503. Speed is 10kn.

What is the set and current strength at the middle portion of Quicks Hole at 1503? Use reference station Cape Cod Canal.

C 271M

S

10.0

WptPan1106 GPS

1435 Course T = 003ºW V = 015ºW M = 018º

QKHG1

BBRR

VSRWNA

MPG1

SPRR2

BBG7

VSBR

VSR28

1503 Visua

l

66

x

x

x x

x1101

M0

1106 GPS

x1151 GPS

C 129M S 7.0

1213

1228

1228

D 1.9

1228

D 1.9

1151 GPS

1300

C

02

0M

S

10

.0

1400

1420 GPS

Set 253M Dft 2.1

CO

G 0

09M

SO

G 8

.7

1420C

0

18

M

S 1

0.0

XTE 0

.2

1435 GPS

1447 Visual

C 271M

S

10.0

1503 Visua

l

VSRWNA

QKHG1

VSR28

VSBR

MPG1

DBG29

77

C 271M

S

10.0

C

066M

S 13.0

27a) T = 051ºW V = 015ºW M = 066º

27b) T= 60D/S T= 60x6.4/13 T= 384/13 T= 29.5/30min 1521 + 0030 ETA 1551

27c) T= 60D/S T= 60x3.5/13 T= 210/13 T= 16.2/16min 1551 + 0016 ETA 1607

27c) Course T = 077ºW V = 015ºW M = 092º

C 092M

S 13.0

D 1.8

1058

C 252M

S 13

1020

C 272M

S 13.0

1027

182M

1027

QKHG1

BBR8

BBBB

BBR8BBG13

QHR2

1503 Visua

l

1521

BBG7

QKHBR

C 0

00M

S

10.0

27) You arrive at Lone Rock BR 1 Qk Fl G at 1521 and change your course to a pre-determined GPS position of L 41º 31.8’ N and Lo 70º 44.5’ W northwest of Weepecket Island in 45’ of water. Speed is 13kn.

27a) What is the True course to the GPS WPT? 051º

27b) What is your ETA at the GPS WPT? 1551

27c) Plot and label final leg of cruise to R “2” Fl R 4sec at entrance to Quissett Harbor. ETA at R “2” 1607

88APPENDIX A - WEEKEND CRUISE

FINISHED

Slide 9

Slide 10

Questions ? … Comments

Vectors have both speed and direction

C105MS 5.0

1000

DR Course = course steered & boat speed

At 1000 you depart position A on a true course of 090º with a boat speed of 5.0 knots.

T-V-M = 090 +15 = 105ºM

At 1050 your GPS position is B vs. DR position of C

D = ST/60 = D = 5.0 x 50 / 60 = 4.16 = 4.2nm

A

1050

1050 GPS

B

Current = direction of flow (set) & speed of current (drift)

Distance from C to B divided by lapsed time is drift

Dft = 60D/T = Dft = 60 x 2.0 / 50 = 2.4kts

and direction from C to B is set.

C

Actual Course = course over ground and speed over ground

Distance from A to B divided by lapsed time is speed over ground

SOG=60D/T = SOG = 60 x 3.1 / 50 = 3.72 = 3.7kts

and direction from A to B is course over ground

Set 2

40M

Dft 2.

4COG131MSOG 3.7

2.0n

m3.1nm

Using known set & drift to determine compass course/course to steer

At 1050 you depart position A for buoy at B with speed of 8.0 knots.

Plot know Current effect = 2.4nm in 1 hour at 225º = starting point C

Swing arc 8.0nm long from C to cross DR course line at D

Direction from C to D is course to steer

T – V – M = 144 + 15 = 159ºM

Replot & label this line from A to determine course is safe should current/drift change.

Distance from A to D is speed = 8.9nm = 8.9kts

ETA at B T=60D/S = T = 60 x 7 / 8.9 = 47.19 = 47min 1050 + 47 = 1137

A

B

C105MS 5.0

1000 1050

1050 GPS

Set 2

40M

Dft 2.

4

COG131MSOG 3.7

CO

G175M

SO

G 8.9

Set 2

40M

Dft 2.

4C

D

C159M

S 8.0

WP01 – buoy R N “2” near entrance to Blackfish Creek WP02 – buoy R N “2” near entrance to Shark RiverWP03 – Latitude N41º 44.0’; Longitude W71º 51.0’ WP04 – buoy RG “D” Fl (2+1) R GONGWP05 – buoy R N “2” near entrance to Perkings Cove WP06 – center of compass roseWP07 – Latitude N41º 38.3’, Longitude W71º 46.5’

WP01

WP02 WP03

WP04

WP05

WP06

WP07

Plot and label your intended route, Leg 1 WP01 to WP02; Leg 2 WP02 to WP03; Leg 3 WP03 to WP04; and Leg 4 WP04 to WP05.

1) What is the total distance of your intended route? 2) What will be the initial compass heading from WP01 to WP02?

WP01

WP02 WP03

WP04

WP05

WP06

WP07

C 3

55M

C 102M

C 061

M

C 1

74M

D 1

0.9

D 6.3

D 3.5

D 8

.9

Using WP07, what is the distance for the danger circle that will encompass the rocks near buoy G “5” Fl G 4sec GONG?

Plot and label a crosstrack error along the first leg that will keep you clear of the rocks southwest of Channel Island.

WP01

WP02 WP03

WP04

WP05

WP06

WP07

C 3

55M

C 102M

C 061

M

C 1

74M

D 1

0.9

D 6.3

D 3.5

D 8

.9

NLT 0.8

XTE 1

.1 S

tbd

Your intentions are to met friends for a raft-up and lunch at WP02. You need to determine the latest time on Saturday you can transit beneath the Tarr Bridge, a fixed span with a charted clearance of 35 feet above MHW and a charted depth of 10 feet at MLLW. For safety reasons, you want at least 38 foot of clearance. You will use the enclosed excerpts from the Bowditch Bay Tide & Current Tables for these calculations. Reference station is Perkins Cove West Jetty.

Your intentions are to met friends for a raft-up and lunch at WP02. You need to determine the latest time on Saturday you can transit beneath the Tarr Bridge, a fixed span with a charted clearance of 35 feet above MHW and a charted depth of 10 feet at MLLW. For safety reasons, you want at least 38 foot of clearance. You will use the enclosed excerpts from the Bowditch Bay Tide & Current Tables for these calculations. Reference station is Perkins Cove West Jetty.

Tarr Bridge 3Perkins Cove West Jetty4 Jul

0548 H1148 L

9.00.4

0009 H0005 L

0.951.00

0557 H1153 L

8.60.4

2336 L -0.3 0005 L 1.00 2341 L -0.3

-0.38.6 8.9

8.9

35 386.49.4

6.4-0.3 6.7

6.77523 36 04 0003 24

0324

You set your sails and at 0830 you pass close-abeam of WP01 on a starboard tack at 4.0kn. As is your practice, you plot your GPS position approximate every hour. Your times and positions along Leg 1 are: 09:27:40 L 41º 36.989’N Lo 71º 55.000’W; 10:30:15 L 41º 38.320’N Lo 71º 58.004’W; 11:30:12 L 41º 40.686’N Lo 71º 56.732’W; 12:26:18 L 41º 42.116’N Lo 71º 59.007’W. Plot and label each position.

WP01

WP02 WP03

WP04

WP05

WP06

WP07

C 3

55M

C 102M

C 061

M

C 1

74M

D 1

0.9

D 6.3

D 3.5

D 8

.9

NLT 0.8

XTE 1

.1 S

tbd

0928 GPS

1030 GPS

1130 GPS

1226 GPS

0830 Visual

At 1230 you receive a VHF call from your friends advising you that they have anchored at position N41º 45.000’, W71º 59.960’. You start your auxiliary engine and make preparation to change course to join your friends. Remembering that practice is the only way to maintain your skills, you decide to plot your position using your radar. You note two distinctive radar returns at 1235 and identify them as buoys R N “2” at a range of 1.3nm and G C “1” at a range of 1.2nm. Plot your position and course to your friends.

WP01

WP02 WP03

WP04

WP05

WP06

WP07

C 3

55M

C 102M

C 061

M

C 1

74M

D 1

0.9

D 6.3

D 3.5

D 8

.9

NLT 0.8

XTE 1

.1 S

tbd

0928 GPS

1030 GPS

1130 GPS

1226 GPS

0830 Visual

WP08

1235 Rada

r

D 1.3D 1.2

C 0

12

M

You arrive at 1310 and raft-up. While discussing the morning’s cruise, you decide to determine your course and speed made good to your 1235 fix.

What is your course made good?What is your speed made good?

WP01

WP02 WP03

WP04

WP05

WP06

WP07

C 3

55M

C 102M

C 061

M

C 1

74M

D 1

0.9

D 6.3

D 3.5

D 8

.9

NLT 0.8

XTE 1

.1 S

tbd

0928 GPS

1030 GPS

1130 GPS

1226 GPS

0830 Visual

WP08

1235 Rada

r

D 1.3D 1.2

C 0

12

M

1310

D = 7.8nm, T = 245minS = (60 x 7.8) / 245 S = 1.91 = 1.9

You depart at 1400 for WP08 using your auxiliary engine at a speed of 6.0 kn. At 1445 you note the beacon on Channel Island abeam to starboard. Plot and label this position. You continue to WP03, arriving at 1530. As the predicted rain clouds are beginning to form you decide to abandon your plan and head directly for Perkins Cove. From past experience, you know the current along the intended route can greatly affect your course. You cut your engine and drift while you determine the new course.

WP01

WP02 WP03

WP04

WP05

WP06

WP07

C 3

55M

C 102M

C 061

M

C 1

74M

D 1

0.9

D 6.3

D 3.5

D 8

.9

NLT 0.8

XTE 1

.1 S

tbd

0928 GPS

1030 GPS

1130 GPS

1226 GPS

0830 Visual

WP08

1235 Rada

r

D 1.3D 1.2

C 0

12

M

13101400

C 113M S 6.0

1445

203

M

1445

1530

You will use the enclosed excerpts from the Bowditch Bay Tide & Current Tables for these calculations. Reference station is Perkins Cove. What is the current set & drift at 1545?

You will use the enclosed excerpts from the Bowditch Bay Tide & Current Tables for these calculations. Reference station is Perkins Cove. What is the current set & drift at 1545?

Tarr Bridge 3Perkins Cove West Jetty

4 Jul

184

1545

1302 0009 13111643 F 1.2 0018 1.9 1701 2.31926 0039 2005

13021643

0341 22177

77 77 77

1302 1419 1536 1643

90 184F 2.3 2.0

Assume your speed made good from your 1400 position to WP03 will be your speed to WP05.

From your 1530 position, what is your course to steer for WP05, taking into account your predicted current.

WP01

WP02 WP03

WP04

WP05

WP06

WP07

C 3

55M

C 102M

C 061

M

C 1

74M

D 1

0.9

D 6.3

D 3.5

D 8

.9

NLT 0.8

XTE 1

.1 S

tbd

0928 GPS

1030 GPS

1130 GPS

1226 GPS

0830 Visual

WP08

1235 Rada

r

D 1.3D 1.2

C 0

12

M

13101400

C 113M S 6.0

1445

203

M

1445

1530

COG

155M

SOG 5.0

D = 6.7, T = 90min S = (60x6.7) / 90 S = 4.46 = 4.5 kn

C 147M

S 4.5

C 147M

S 4.5

Set

2.0

D

rf199

M