In May 1916, the explorer Ernest Shackleton and four of his men were approaching the end of a gruelling ordeal. They had left the rest of the crew of Shackleton’s ship Endurance stranded on Elephant Island in the Antarctic, while they attempted to cross the Southern Ocean to the island of South Georgia. They were sailing in a small lifeboat in the infamous Drake Passage, which was living up to its reputation as the roughest stretch of water on the planet. On 5th May Shackelton saw what he thought was a break in the weather. He later recorded that “at midnight I was at the tiller and suddenly noticed a line of clear sky between the south and south-west. I called to the other men that the sky was clearing, and then a moment later I realised that what I had seen was not a rift in the clouds but the white crest of an enormous wave.”
The wave was bigger than any Shackleton had encountered in 26 years at sea. It reared over the boat like a wall, blocking the wind and becalming them in its lee. Then it struck, and Shackleton reported that the boat was “lifted and flung forward like a cork in breaking surf.” Amazingly it survived the seething chaos, though it half-filled with water. After 10 minutes of desperate baling the crew were thoroughly soaked but safe. They arrived at South Georgia three days later.
For centuries sailors have told stories of enormous waves that swept the oceans and could sink a ship in an instant, but they were rarely believed by landsmen. However, in recent years, evidence for such phenomena has begun to mount up. In December 1978 the German Freighter Munchen sent out a garbled Mayday message while crossing the Atlantic. When rescuers reached the scene, only scattered wreckage was found, including a lifeboat ripped from its mounting point, twenty meters up on the ship’s superstructure, by what must have been an astonishing force.
With the opening up of the North Sea between Scotland and Norway for oil exploration came the first scientific evidence of the existence of rogue waves. Oil platforms standing on the seabed are so massive that they are able to withstand the impact of a rogue wave, and survive to tell the tale. In 1984 the Gorm platform in the central North Sea detected a wave that was 11 metres high, on a sea that was otherwise relatively calm. Ten years later the Draupner oil platform, which was fitted with automatic wave height recording equipment, noted a wave that was 25.6 metres tall, that is 84 feet. The impact of the wave inflicted damage to the platform far above sea level, confirming the wave’s height. A rogue wave then, rather than a rogue reading.
Some of the world’s larger ships have also encountered rogue waves and survived. The most famous incident occurred in 1995 to the Queen Elizabeth II crossing between Southampton and New York. Her master, Captain Ronald Warwick, reported that “out of the darkness came this great wall of water...enormous, like the white cliffs of Dover.” The liner only survived the impact of the 29 metre wave thanks to her size, and Warwick turning his ship so that she could effectively surf the wave.
Rogue waves are now an established fact, and have almost certainly been responsible for hundreds of unexplained disappearances at sea over the centuries. In 2004 scientists used three weeks of radar images from European Space Agency satellites to survey the oceans of the world. They found ten rogue waves of 25 metres (82 feet) or higher.
A rogue wave is now understood to be a natural ocean phenomenon that only lasts briefly, occurs in a limited location, and most often happens far out at sea. Although rare, they are potentially very dangerous, since their power goes far beyond the usual expectations of ship designers, and can overwhelm the capabilities of ocean-going vessels. For ships at sea they are far more dangerous than Tsunamis, which are almost unnoticeable in deep water and only become life-threatening as they approach the shoreline.
Now that they are proven phenomena, oceanographers around the globe are working on understanding how they form, so that forecasting can be put in place to alert shipping to their presence. It is to be hoped that their work will be successful, because US researchers looking back into previously unexplained ship disappearances in the twentieth century have identified at least fifty that are attributable to rogue waves, to add to all the previous ones put down to sailors and their tall tales.