From that targeting tutorial:
Quote:
For example, if the length of the measurement is .3km (or 300m),
then the speed of the target is 3 knots. 500m is 5 knots, etc.
|
The 3:15 rule is for measurments in metric, but speed in KNOTS.
The problem with the last example Paul gave in post 10 is that the 0.7 is DIFFERENT---in the metric example it's .7km, and in the imperial it's .7nm. In the imperial it's 0.7 nautical miles measured, so you are not comparing the same speeds at all.
3:15 ONLY applies if your ruler measures km, but your speeds are still in knots.
3 minute/6 minute rule always applies as long as the units used in the ruler and speed are the same. nm/knots, or km/kph
tater