Waves of Data for Maverick’s Surf Competition

Maverick’s, a famous surf spot and big-wave surf competition near Half Moon Bay, is named after an intrepid dog who used to paddle out to join his owner in thunderous swells. The name evokes an independent spirit, unconventional and unafraid to go against the crowd. Frank Oppenheimer, who founded the Exploratorium in 1969, was a maverick for re-inventing the museum as a place where people could learn about science by messing around with it.

This year’s Titans of Maverick’s competition will feature women for the first time ever, including a local girl, Bianca Valenti,  who came to the Exploratorium recently with filmmaker Sachi Cunningham. Sachi previewed a trailer from her upcoming movie about the first female big wave competitors, featuring Bianca (still being shot, but for a taste of Sachi’s work, check out this documentary she did for the Los Angeles Times).  

The ladies were invited by Exploratorium educator Lori Lambertson, a surfer herself, as part of  a primer she gave recently recently on big waves and big data. It was everything you need to know about whether and when Maverick’s organizers will call up Bianca and the other competitors with 48 hours warning to travel to Northern California ready to battle it out.

So while we wait to see whether the Maverick’s surf competition will happen (we’re still in the event window which closes on March 31), you might wonder why it’s not held every year. What’s so special about clean 30-plus-foot waves? If you live near a Northern California beach, you know that big waves aren’t so rare in winter. But for the building blocks of a perfect swell, you need to look farther off shore at conditions in the middle of the Pacific days before those waves reach this fabled surf spot 25 miles south of San Francisco. 

Big waves come from big winds, which are stronger in our winter because of the vast temperature difference between the North Pole and the equator. Earth’s atmosphere tries to balance the differential by moving air masses around, which clash over the ocean and generate storms and strong winds. Winds blowing across the ocean surface create ripples which, with repeated gusts, grow into waves. The stronger the  wind, the larger the waves. Waves emerge from these Pacific storms at different speeds, the waves with the longest wave lengths moving faster than the shorter, choppier waves. Racing across the Pacific, these big, organized swells move westward where they are detected by a string of buoys operated by the National Oceanic and Atmospheric Administration. The one to pay attention to is Buoy #46006 known as South Papa. Like all NOAA buoys it measures wind, water temperature, and the size and orientation of the waves as they approach Northern California, providing about one days warning for potentially favorable waves.

But a large approaching swell is only one of the ingredients needed before organizers summon surfers from all over the world to grab their boards and wetsuits and catch a plane to San Francisco. Organizers also need to know when the surf will arrive—if it’s at night, the competition can’t be held. Direction is also important for the offshore break, which happens when the waves encounter an underwater shelf, called “the ramp,” and begin to slow. Deep troughs on either side of the ramp, focus the wave energy into a V shape. As the wave travels over the reef, friction slows the underside of the swell while the top keeps moving, cresting and crashing in a powerful break that can reach up to 60 feet in height.  The bathymetry is just right for big waves that come approximately due west, if they come from the northwest, the Farrallon Islands and Cordell Bank break up the swell before it reaches Maverick’s.

Being able to predict surf conditions 48-72 hours in advance is an art and science that few have perfected. To make “the call” for Maverick’s, you need to take into account all the data about wave height, direction and speed, and wind and marine weather predictions coming from NOAA and putting them into a computer model (a set of mathematical formulas called algorithms) to generate a surf forecast. The most widely-used Maverick’s forecast, stormsurf.com,  was developed by Mark Sponsler  and is based on his years of experience watching and surfing waves in Northern California and running computer trials. Considered the best, Mark’s model is based on trial and error, running the model backwards (called hind casting) and forwards and continuing to tweak all the variations, known as starting conditions, that he can measure. His algorithm is a secret, but he makes the forecast available through his website. 

So, if you want a head’s up about this year’s Maverick’s competition, keep an eye on Pacific storms, a buoy named Papa, and Mr. Sponsler’s surf forecast. We hope to have a live feed up at the Exploratorium, where we’ll be cheering for Bianca and all the other brave souls who live for 3-story waves to ride.