Freaks Of Nature

Understanding Rogue—or, Freak—Waves.

- Dag Pike

Wild storms make for wild seas, and for hundreds of years sailors have returned to harbor with tales of encountering huge waves in the ocean. They may be called rogue waves or freak waves, but these are really extreme waves that deviate dramatically from the regular wave pattern. Once considered to be the product of imaginative sailors’ minds, extreme waves earned credibility as authoritative reports started to emerge. Dramatic photos reinforced the reports. Today, sophisticated wave-measuring technology and satellite observations help detect these waves, and a 100-foot monster wave has now been experienced—and verified—in the Atlantic.

For the cruising skipper, rogue waves are something to take into account when planning a passage. Calculations from the British National Institute of Oceanography, using a random process formula, suggest that if you take the average height of waves in a train, 1 in 23 waves will be twice the average height, and one wave in 1,175 will be three times the average height. While those figures might give sailors pause for thought, the additional chilling statistic is that one wave in 300,000 will be four times the average height of the wave train. Think about that—you have the prospect of meeting a 60-foot wave when the average height is just 15 feet. However, to put this into perspective, 300,000 is an awful lot of waves, and that equates to only one extreme wave of that size every 6,000 miles. Even then, extreme waves tend to occur only in conditions that you will have tried to avoid anyway. In 65 years at sea, I have experienced three rogue waves, and these monsters appeared only during winds of gale force or stronger.

MY “FREAKS”