1. Lesson 8: Dead Reckoning
“Getting Acquainted Lecture”
Instructor Bio:
Commissioned May, 1993; NROTC Unit, IIT
Reported to Hue City (CG-66) homeported in Mayport, FL for a 42 mos tour
24 mos - Engineering Dept (Auxiliaries Officer & Damage Control Assistant)
18 mos - Operations Dept (Air Warfare Officer/BW Flag Liaison Officer)
Command Employment (while aboard Hue City)
1995 Med Deployment 95-2 with USS Theodore Roosevelt
1996 Baltops ‘96 (Scandinavian countries)
1997 Med Deployment 97-2 with USS John F. Kennedy
Midshipmen Cruises (emphasize student contribution to course)
CV (CV 63) - Secrest
Tico’s (LKE, VLG) -Waterston, Pope, Sullivan
Burkes (DDG 61) - Kuckel
OH Perry (FFG 61) - Phillips
LHA/LHD (LSD 44) - Fink, Sutherland
AOE (AOE-8) - Hertel
Review Syllabus:
Course objectives
Course resources (webpage, Textbook, Workbook)
Case studies - provide vivid and intriguing examples of the the fundamental principles taught in this course.
9/15/2018
Lesson 8: Dead Reckoning

2. Lesson 7: Dead Reckoning
AGENDA:
Definition of Dead Reckoning
Six Rules of Dead Reckoning
Define/Apply the 3 min & 6 min Rules
Applicable reading: Hobbs pg 1

3. Dead Reckoning
DR is the process of determining a ship’s approximate position by applying, from a known position, a vector or a series of consecutive vectors representing the true courses steered and the distance run as determined by the ship’s speed and time, without considering the effects of wind and current.

4. Dead Reckoning
DR is derived from DEDUCED, or DED, reckoning which was the process by which a vessel’s position was computed trigonometrically in relation to a known point of departure.
This is performed as often as required by the 6 rules of DR
Uses:
Determine present position
Project future positions relative to hazards
Measure the effects of current (winds, seas)
Alter course to account the effects of current

5. Six Rules of DR

6. Plot a new Course Line with Every Fix or Running Fix
0846
c-075
s-15
0937 R-Fix
c-106
s-10

7. Plot a DR Position Every Hour on the Hour
0900
1000
1100

8. Plot a DR Position at Every Course Change29 20
c-090
C-125
C-080 24

9. Plot a DR Position at Every Speed Change21 27 15
S-10
S-15
S-5

10. Plot a DR Position for Every Line of Position (LOP)
c-195
s-10
Tank
0826
0826

11. Plot a DR Position for Every Fix or Running Fix
0846 46 37
0937
R-Fix

12. Speed-Time-Distance Calculations
STD calculations can be made 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

13. 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

14. Six Minute Rule
In 6 minutes a vessel travels in miles a distance equal to its speed in knots divided by 10.
D = S / 10
where: D = distance traveled (nm)
S = speed in knots

15. HOMEWORK

16. REVIEW
What is Dead Reckoning?
What are the 6 Rules of DR?