- Open your stopwatch
- Mark the current position of a contact as close as you can
- Start the stopwatch, after 3 minutes and 15 seconds...
- Mark the current position of the contact as close as you can
- Measure the distance between the two marks. Divide by 100 to get the speed in knots.
So if the distance was 800m they are traveling 8kts. If it was 1100m they are traveling 11kts
Step 1 & 2 & 3:
Step 4:
Step 5:
For Imperial users (huh??) only measure for 3 minutes.