The 3 and 6 minute rule?

Answer 1

The 3 and 6 minute rules are used to quickly solve for distance in Nautical Navigation. The principles are then applied to other navigation principles including Rapid Radar Plotting and other tools. Basically these rules are used to quickly determining distance traveled in 3 and 6 minutes.

The premise with these rules is that a Nautical Mile (NM) = 2000 yards (yds)

Additionally, 1 knot (kt) = 1 NM / hr = 2000 yds/hr (this is the equivalent to MPH)

3 Minute Rule:

Speed (kts) * 100 = Distance (yds) traveled in 3 minutes

Example: if traveling 20 knots, the distance you've traveled in 3 minutes is as follows:

20kts *100 = 2000yds

for 15 knots, 15kts * 100 = 1500yds

6 Minute Rule:

Speed (kts) / 10 = Distance (NM) traveled in 6 minutes

Example: if traveling 20 knots, the distance you've traveled in 6 minutes is as follows:

20kts / 10 = 2NM

for 15 knots: 15kts / 10 = 1.5NM