Question 127Navigation General

The correct answer is B) east side of the mark. Under the IALA (International Association of Marine Aids to Navigation and Lighthouse Authorities) cardinal system, a mark with a quick white light showing 3 flashes every 10 seconds indicates that the safest water is on the east side of the mark. This is because the cardinal system uses the number of flashes to indicate the cardinal direction, with 3 flashes signifying the east cardinal mark. The other options are incorrect because a north cardinal mark would have 1 flash, a south cardinal mark would have 2 flashes, and a west cardinal mark would have 4 flashes. The 3 flashes in the question specifically indicate an east cardinal mark, meaning the safest water is on the east side of the mark.