Wave Defense

If the MaxWave study is correct, and rogue waves are much more common than previously thought, does that mean oceangoing vessels are far riskier than we thought? It might. Ships and offshore structures, such as oil rigs, are built to withstand a certain significant wave height, whatever is determined that the ship is likely to encounter in its lifetime. Few are built to handle 100-foot waves. Furthermore, a ship's ability to withstand a strike by a rogue wave depends in large part on the ballast, or stability. If a ship has the right amount of ballast and is floating at the proper level, it will be more likely to right itself after being pushed over by a wave [source: Smith, 233]. Today's international shipping laws don't necessarily take frequent rogue waves into account where ship construction and maintenance are concerned. But that's not to say all ships are unsafe -- perhaps it would be impossible to build a ship that could withstand any wave.

Three Sisters
Rogue waves do not always come alone. A phenomenon well known to sailors is the "Three Sisters." After one huge wave has passed, it may be followed by two more. These trios of monster waves can be especially devastating -- the first can disable a ship and leave it unable to maneuver itself to avoid or ride out the subsequent waves.

And it's not just ships and offshore structures that need to worry about rogue waves. These walls of water may pose a serious threat even to people who aren't on the water. The U.S. Navy has expressed concern that some Coast Guard rescue helicopters lost at sea may have been struck by rogue waves [source: U.S. Naval Institute]. And shorelines where there is a steep drop-off to deep ocean close to shore can be dangerous for those exploring the rocks. Unexpected waves have been known to sweep people off the rocks, where the undertow drags them down and away.

Currently, it is impossible to predict a rogue wave. However, MaxWave and WaveAtlas could give scientists and sailors a good look at the conditions that cause rogue waves, as well as indicate areas where they happen most often. This could allow shipping routes to take into account particularly dangerous areas when the weather conditions could lead to rogues. Avoiding these areas could save hundreds of lives every year.

Rogue versus Tsunami
When you think of giant, frightening, destructive waves, tsunamis definitely come to mind. But don't confuse these giant waves with rogues -- while both can be catastrophic, they are quite different. The easiest way to remember the difference is by what causes the "wall of water" and where the destruction from it occurs.

Tsunamis are most often caused by undersea earthquakes, which send tons of rock shooting upward with tremendous force. The energy of that force is transferred to the water. So, unlike normal waves that are caused by wind forces, the driving energy of a tsunami moves through the water, not on top of it. Therefore, as the tsunami travels through deep water -- at up to 500 or 600 miles per hour -- it's barely evident above water. A tsunami is typically no more than 3 feet (1 meter) high. Of course, all that changes as the tsunami nears the coastline. It is then that it attains frightening height and achieves its more recognizable and disastrous form.

Rogue waves, as we've discussed in this article, arise seemingly out of nowhere, and they can attain their massive heights in deep water, not just along the shoreline.

For more information on rogue waves and related topics, check out the links on the next page.