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- Jan 26, 2002
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When somebody talks about waves higher than 50 feet, is is usually garbage. Often they are estimating difference between crest and trough, and then that is exagerated. Wave amplitude is 1/2 the height from crest to trough. Not that it isn't hard to be objective when in the trough of even a moderately sized wave. Hard to measure too.
Another reason to be skeptical is that the person is there to make the claim--an encounter with such a wave will often sink or severely damage even the largest of ships:
But recent data including a satellite study shows that 25 m waves are not as uncommon as previously thought.
Ship-sinking monster waves revealed by ESA satellites
21 July 2004
Once dismissed as a nautical myth, freakish ocean waves that rise as tall as ten-storey apartment blocks have been accepted as a leading cause of large ship sinkings. Results from ESA's ERS satellites helped establish the widespread existence of these 'rogue' waves and are now being used to study their origins...
...Severe weather has sunk more than 200 supertankers and container ships exceeding 200 metres in length during the last two decades. Rogue waves are believed to be the major cause in many such cases...
...two large ships sink every week on average, but the cause is never studied to the same detail as an air crash. It simply gets put down to 'bad weather'...
...Objective radar evidence from this and other platforms radar data from the North Sea's Goma oilfield recorded 466 rogue wave encounters in 12 years - helped convert previously sceptical scientists, whose statistics showed such large deviations from the surrounding sea state should occur only once every 10000 years.
The fact that rogue waves actually take place relatively frequently had major safety and economic implications, since current ships and offshore platforms are built to withstand maximum wave heights of only 15 metres...
..."ESA provided us with three weeks' worth of data around 30,000 separate imagettes selected around the time that the Bremen and Caledonian Star were struck. The images were processed and automatically searched for extreme waves at the German Aerospace Centre (DLR)."
Despite the relatively brief length of time the data covered, the MaxWave team identified more than ten individual giant waves around the globe above 25 metres in height...
Surely more likely to get struck by lightening, but pretty amazing, none the less. Good thing they occur individually, hard to imagine any vessel surviving an encounter with more than one!
But it is worth remembering that even in ordinary storms, a rogue wave much larger than the rest can occur. A small craft coping with 15 foot waves may encounter a 30-footer, and that's nothing to sneeze at. Such waves can and have ripped the cabin roof right off the deck. That's how boats can vanish without a trace.
For anyone interested in reading about what such things are like, preferably while in a warm, dry place, the book "Heavy Weather Sailing" by K. Adlard Coles, is a fine book with both compelling accounts, detailed analysis, and quite amazing photos of things that rarely get photographed. It is a classic standard, and the 30th Anniversary Edition that I found in my local library contains lots of new additions--lot of stuff in older versions has been replaced because the intent of the book is to provide information that reflects current technology. So reading an old version, and the newest version provides almost twice as many stories.
Another reason to be skeptical is that the person is there to make the claim--an encounter with such a wave will often sink or severely damage even the largest of ships:
But recent data including a satellite study shows that 25 m waves are not as uncommon as previously thought.
Ship-sinking monster waves revealed by ESA satellites
21 July 2004
Once dismissed as a nautical myth, freakish ocean waves that rise as tall as ten-storey apartment blocks have been accepted as a leading cause of large ship sinkings. Results from ESA's ERS satellites helped establish the widespread existence of these 'rogue' waves and are now being used to study their origins...
...Severe weather has sunk more than 200 supertankers and container ships exceeding 200 metres in length during the last two decades. Rogue waves are believed to be the major cause in many such cases...
...two large ships sink every week on average, but the cause is never studied to the same detail as an air crash. It simply gets put down to 'bad weather'...
...Objective radar evidence from this and other platforms radar data from the North Sea's Goma oilfield recorded 466 rogue wave encounters in 12 years - helped convert previously sceptical scientists, whose statistics showed such large deviations from the surrounding sea state should occur only once every 10000 years.
The fact that rogue waves actually take place relatively frequently had major safety and economic implications, since current ships and offshore platforms are built to withstand maximum wave heights of only 15 metres...
..."ESA provided us with three weeks' worth of data around 30,000 separate imagettes selected around the time that the Bremen and Caledonian Star were struck. The images were processed and automatically searched for extreme waves at the German Aerospace Centre (DLR)."
Despite the relatively brief length of time the data covered, the MaxWave team identified more than ten individual giant waves around the globe above 25 metres in height...
Surely more likely to get struck by lightening, but pretty amazing, none the less. Good thing they occur individually, hard to imagine any vessel surviving an encounter with more than one!
But it is worth remembering that even in ordinary storms, a rogue wave much larger than the rest can occur. A small craft coping with 15 foot waves may encounter a 30-footer, and that's nothing to sneeze at. Such waves can and have ripped the cabin roof right off the deck. That's how boats can vanish without a trace.
For anyone interested in reading about what such things are like, preferably while in a warm, dry place, the book "Heavy Weather Sailing" by K. Adlard Coles, is a fine book with both compelling accounts, detailed analysis, and quite amazing photos of things that rarely get photographed. It is a classic standard, and the 30th Anniversary Edition that I found in my local library contains lots of new additions--lot of stuff in older versions has been replaced because the intent of the book is to provide information that reflects current technology. So reading an old version, and the newest version provides almost twice as many stories.
