Ghost Wave - Chris Dixon [58]
Sean Collins saw a documentary film about Munk’s work and it set him on a path.
“Munk scientifically confirmed to us surfers what we already knew—that some of our best swells were from the Southern Hemisphere. But back then for us it was all coconut telegraph—someone talking about a big storm in New Zealand and trying to follow it. Then getting reports from Tahiti, with the swell seven days from us, then Hawaii with it two days away, and then anticipating the swell’s arrival in California. But it was really hit or miss. Not all those swells would even make it to California.
“Back in the seventies nobody really had a clue about real forecasting. I couldn’t use Munk’s work since I wasn’t a calculus whiz—I just wasn’t smart enough. And most of the oceanographic papers that I found in the Federal Depository libraries and weather service offices were far too complicated for me to fully understand. So Southern Hemisphere swells were still just mystical rumors. We’re relying on storms sending waves from between five and ten thousand miles away. All of a sudden a swell would just show up. It would be flat and 1 foot one day, and the very next morning it would be 8 to 10 feet. It was like Christmas. That’s where the whole ‘surf’s up’ thing came from. You drop what you’re doing, run to the beach, and jump on it—because it was a ‘good today, gone tomorrow’ kind of thing.”
One bright day in late 1979, Collins posted up on the roof of his house and flipped open a notebook to watch the waves running up against the Seal Beach jetty. His work quickly evolved into a fanatical obsession—a daily log of height, angle of approach, seconds between individual waves, minutes between sets of waves, and the number of waves in each set. Collins then bought a clunky old marine fax machine capable of decoding the crackling beeps and chirps broadcast via shortwave from Christchurch, New Zealand. The clearest signal arrived at three in the morning, and the printouts of swirls and isobars gave only the crudest information about wind speeds and pressure gradients. But the images could be held up one after the other, allowing for a rough animation of how storms and their winds were evolving. He learned, like Munk, to hindcast.
“I was kind of like my own virtual buoy,” he says. “And that just really taught me about swells. Southern Hemi swells were the hardest to forecast. They were like a black hole. You could hardly get satellite photos back then. I’d get those weather-fax charts and keep a library every single day. You could backtrack to determine size, timing, swell period. When we’d get really good waves, I could measure the swell period and tell how fast the swell actually traveled in deep water, so I could reverse it and go back to the point of origin. That would tell the location and date where those waves came from by the speed of their travel. I taught myself what to look for—this storm didn’t look all that good, but the swell it produced was incredible—why did that happen? Over a few years, I got to a point where I was about 75 to 80 percent accurate.”
This image shows the effect of a constant forty-knot wind on the surface of the ocean. After one hundred miles, a swell is fifteen feet tall and two hundred feet deep with a ten-second period from trough to crest. After two thousand miles, it’s thirty-seven feet tall and one thousand feet deep and carries a twenty-second period—and orders of magnitude more power. A swell like this could create a perfect breaking wave more than a hundred feet tall atop the Cortes Bank. Image courtesy: Sean Collins/Surfline.
Collins amazed his friends when he showed up unexpectedly one day at their Baja campsite with his weather-fax. He strung the antenna wire around his tent and juiced the machine with his car battery. He told Sam George and his fellow campers, “Watch this, tomorrow it’s going to be six to eight feet.”
George says, laughing: “We were living in a tent, and he was getting faxes from the weather service. It was just unbelievable technology. All I knew