Tide and Current Apps Capt. Patricia Ensworth Manhattan Sailing Club March 18 2014.
Lesson 13 Dr And Current Sailing
18
Light 9 9 9 9 9 9 9 9 9 9 9 5 5 5 5 11 11 11 11 11 11 11 11 6 pa FL 6s 58ft 9M Tank L ong Point 20 20 20 20 20 20 21 20 20 20 21 21 21 21 21 21 23 23 23 23 23 23 15 15 15 15 17 17 17 17 19 19 19 19 C- 085 T S - 12 08 00 0 8 10 0810 Fundamentals of Naval Science Dead Reckoning and Current Sailing
-
Upload
guilherme-azevedo -
Category
Education
-
view
8.434 -
download
1
description
Transcript of Lesson 13 Dr And Current Sailing
Light
9
99 9
99
999 9 95 5
5
5
11 1111
1111
1111
11
6pa
FL 6s 58ft 9M
Tank
Long Point
20
20 2
020
20
20 212
0
20
20
2121
21 2121 2123 23 23 23 23 23
1515 15 1517
1717 1719
19 19 19
C- 085 TS - 12
080008
100810
Fundamentals ofNaval Science
Dead Reckoning and Current
Sailing
Dead Reckoning• DR - Determining the position of a
vessel by adding to the last fix the ship’s true course and speed for a given time.
Dead Reckoning• Uses:
– Determine when change course/speed– To predict the time of sighting lights and other aids to navigation
– Project future positions relative to hazards– Measure the effects of current (winds, seas)– Alter course to account the effects of current
Plot a DR Position Every Hour on the Hour
09001000
1100
Plot a DR Position atEvery Course Change
20
24
29C-125
c-090
C-080
Plot a DR Position atEvery Speed Change
15 21 27
S-10 S-15 S-5
Plot a DR Position for Every Line of Position (LOP)
Tank
0826
0826c-1
95s-1
0
Plot a DR Position for Every Fix or Running Fix
46
0846
370937R-Fix
0846c-106s-10 52
58
A new course line shall be drawn from every fix with 2 DRs
at your fix interval
Typical DR plot
Speed-Time-Distance Calculations • using a nautical slide rule,
electronic calculator, set of pre-computed tables, or speed nomogram.
D = S x T where: D = distance traveled S = speed in knots
T = time in hours
Three Minute Rule In 3 minutes a vessel travels in yards a
distance 100 times its speed in knots. D = S x 100
where: D = distance traveled (yds) S = speed in knots
Six Minute Rule In 6 minutes a vessel travels in miles a distance equal to its speed in knots divided by 10.
D = S / 10where: D = distance traveled (nm)
S = speed in knots
Terms Used in Current Sailing Track (TR)
Speed of Advance (SOA) Course (C) Speed (S)
Terms Used in Current Sailing
Set (S) Drift (D)
Course Made Good (CMG)Speed Made Good (SMG)
Sensibility Check 1. Current pushing ahead, decrease speed.
2. Current pushing astern, increase speed.
3. Current pushing left, steer more to the right.
4. Current pushing right, steer more to the left.
