Three boys stand on a log. An adult couple walks by 20 feet down the beach. That scene is not recorded, but presumably it's what was happening just before video began to capture a moment of fright on Oct. 24, 2010, at Rockaway Beach, Ore.
The video shows three boys sent tumbling off their log as every visible part of the beach is rapidly inundated by a surging wave that seems like it will never relent.
Two of the boys struggle to gain their footing in the surge, and just as soon as they do a much longer log hits them in the legs, cartwheeling them face-first into the water. The third boy, up to his neck in water, can't even get to his feet before he is swept about 15 feet down the beach by the second log and nearly pinned between third and fourth logs, one of them just missing his head as it rushes by.
By the time the recording begins, the couple who had been walking by have already been knocked down. One of them floats uncontrollably for about 20 feet, and only regains footing when the surge begins to recede. The other floats away, belly-down, for 30 feet, struggling to keep head above water, and has to be helped up after a sixth person runs out to assist. The person who is helped up staggers back to high ground, leaning on the rescuer for support.
As with giant squid or Siberian meteor blasts, the ubiquity of the video camera has revealed the secrets of another of nature's elusive elements: the sneaker wave.
Sneaker waves are broadly defined as any wave that sneaks up on people, but the most alarming and all-too-
real among them are those that rise far higher on the beach than waves before or after, and they can be killers.
"In Humboldt and Del Norte counties, in the last 10 years, we've lost about three to five people per year, so it's a pretty major killer," says Troy Nicolini, warning coordination meteorologist at the National Weather Service's Eureka office.
Perhaps the most startling illustration of sneaker waves caught on camera - and there are many videos of this particular day online - comes from the Mavericks Surf Contest of 2010 near Half Moon Bay. Boasting big and even deadly waves known to surfers worldwide, the contest is held when conditions are prime (after a winter storm) and when waves off the coast can top out at 80 feet.
Attracting big sponsors and held in a surfing-popular region, the contest draws thousands of spectators, and so it was on Feb. 13 of that year that there were hundreds of people, several large scaffoldings and multiple canopies on the beach when a massive wave - far larger than preceding waves - crashed over a breakwall and flooded the whole area, washing people across the area in a seething blanket of whitewater that was as much as 3 feet deep when it first struck spectators.
Scaffolding and canopies collapsed. People who were dragged around the beach uncontrollably suffered injuries including broken bones.
The crowd had been warned that the beach in high surf conditions was unsafe, but many did not listen. Incredibly, people kept returning to the beach, and there were two more sneaker waves that crashed over the breakwall and inflicted more injuries on the foolish.
The Mavericks 2010 waves illustrate most of all the recklessness and stubbornness with which people can dismiss the danger of waves - repeatedly. But they are not the best example of the sneakiest sneakers.
High surf days like the one at Mavericks are less likely to claim lives from sneaker waves than days when the waves generally appear to be calm and steady, Nicolini says, in part because the high surf warns people to stay away (at least those who aren't dying to see a surf competition).
"If there are days when the ocean looks flat, that's the scenario that often gets people in trouble," Nicolini says.
But don't let any of this scare you away from the beach. Scientists, including Nicolini, are making progress in understanding the dynamics of sneaker waves and are thus able to offer new insight into how one can distinguish seas that only appear harmless from those that truly are.
Upcoming editions of Vista Point will discuss how you can tell the difference between truly safe waters and those that present only the illusion of safety, how sneaker waves occur, and the implications all of this has for the safety of beach and jetty access.
Reach assistant editor Matthew C. Durkee at firstname.lastname@example.org.