Giant waves

Last week, New Zealand media reported the biggest wave ever recorded - by a newly deployed buoy in the Southern Ocean, near Auckland and Campbell islands, sites of many shipwrecks in the days of storm-battered tall ships.

The wave, measured at 19.4 metres -- just under 64 feet -- was higher than a five-storey building, yet scientists say that those that get away without being measured are even bigger.  And waves are due to get even bigger as climate change takes hold.

Huge waves are nothing new, though.  For centuries sailors have been relating yarns of gigantic waves, while countless ships have silently foundered, lost without apparent reason, leaving no trace.

The BBC has created a wonderful picture album, under the heading "Terrifying 20-metre rogue-waves are actually real."

As Nic Fleming writes, "TEN-storey high, near-vertical walls of frothing water. Smashed portholes and flooded cabins on the upper decks. Thirty-metre behemoths that rise up from nowhere to throw ships about like corks, only to slip back beneath the depths moments later. 

"Evocative descriptions of abnormally large "rogue waves" that appear out of the blue have been shared among sailors for centuries. With little or no hard evidence, and the size of the waves often growing with each telling, there is little surprise that scientists long dismissed them as tall tales.

"Until around half a century ago, this scepticism chimed with the scientific evidence. According to scientists' best understanding of how waves are generated, a 30m wave might be expected once every 30,000 years. Rogue waves could safely be classified alongside mermaids and sea monsters.

"However, we now know that they are no maritime myths."

"The Great Wave off Kanagawa" by Katsushika Hokusai (Credit: Universal Art Archive/Alamy