
What is the following number in this sequence: 3, 6, 9, … ? Its obviously 12. The cardinal buoys are set up this way, following time on a clock: 3 flashes for east, 6 flashes for north, 9 flashes for west… and 60 flashes for north. North is breaking the pattern!
It may be so because breaking the pattern makes it easier to distinguish the north from the west in a low visibility setting.