03 - Fixes, Running Fixes, Dead Reckoning

Question 1

Dead Reckoning

Answer 1

• Based on the ship’s ordered course and speed
  
  • Ship’s future position

Question 2

Six rules of DR

Answer 2

1. At least every hour on the hour in open ocean
2. At least every course change
3. At every speed change
4. After every fix or running fix
5. When obtaining a single LOP
6. Label each fix with course, speed, time, and draw a new course line from each fix or running fix. DR plot should cover at least the next two fix intervals.

Question 3

Time-Speed-Distance Calculations

Answer 3

D = S x T

• D = Distance in nm
• S = Speed in knots
• T = Time in hours

Question 4

3-min rule

Answer 4

Distance traveled of a ship in yards in three minutes is equal to its speed in knots multiplied by 100.

D = S x 100

Question 5

6-min rule

Answer 5

Distance of travel of a ship in nautical miles in six minutes is equal to its speed in knots divided by 10.

D = S/10

Question 6

Running Fix

Answer 6

A method for determing the ship’s position with visual LOPs when only one object is visible