When Hurricane Guillermo churned up the waters off Mexico 10 days ago, local boaters, fishermen and surfers already knew it would send powerful waves thousands of miles north to pummel Ventura County's coastline.
Predicting the waves over the horizon has become increasingly easy through commercial weather and wave forecasters and free Internet sites that compile weather data and wave information.
Lifeguards at Port Hueneme Beach, for instance, already knew last weekend that they would see waves topping 12 feet by midweek.
The advance notice enabled them to issue warnings about treacherous surf and coastal rip currents, and close the surf zone to swimmers to protect the public health.
"Forecasting allows us to prepare," said 24-year-old lifeguard Jonas White, while watching the waves churn up white water at the Port Hueneme pier. "A lot of times a predicted swell doesn't come, but when they do, we are ready with extra people on duty."
Such forecasting allows seafaring barges laden with expensive equipment to elude devastation.
Rea Strange, a local weather and wave forecaster of more than three decades, sized up the swells produced by Guillermo in time to warn one of his clients--a barge operator with equipment afloat near Tijuana.
The barge was moved to safe harbor, Strange said, to ride out the big seas.
For others, predicting a big swell is more sport than anything else. It can mean the difference between catching waves and catching nothing.
When Guillermo-generated surf began to crash along Ventura's coast last week, Lee Westfall, 17, of Thousand Oaks was ready.
Westfall didn't smell the big waves coming on the wind or feel some strange cosmic vibe. He knew the waves would be good at Leo Carrillo State Beach because the news arrived via fax.
"I knew it'd be big down there 'cause it said it would," the teenager said.
Other surfers packed the lineup at Ventura's Surfers Point because they had made a phone call, or tapped into the Internet and found out a big south swell would be hitting.
Many surfers--especially the landlocked ones--have become dependent on professional wave forecasters who offer predictions on one-sheet faxes or on recorded announcements accessible with a toll call.
WaveFax, which is the biggest of the swell forecasters, offers weather and swell predictions for California, Hawaii, Mexico and Central America for $10 a month, said Sean Collins of Surfline/Wavetrak in Orange County.
Collins has 100 surf reporters who provide updated information on conditions and coming swells on both the coasts and in Hawaii.
The company also provides a service that will call or page a subscriber when the surf's up, Collins said.
But for cash-strapped surfers or those who are just plain cheap, there is also a slew of free services.
One is the National Weather Service's radio broadcast, which includes information on the height and direction of waves detected by a system of buoys tethered along the California coast. Using more sophisticated sensors on an offshore oil platform, the Scripps Institution of Oceanography provides even more detailed information, along with swell forecasting on its Web site.
Ventura surfer Peter Miller, 30, said he doesn't like the idea of paying for wave information.
"Well, I'm Scottish and I don't like paying for anything," Miller said.
It takes some time and experience to make sense of complicated--but free--weather maps of the Pacific Ocean covered with isobars demarcating high- and low-pressure systems and wind-flow patterns. But Miller, like many other surfers, has become something of an amateur meteorologist.