John Florence, Kelly Slater's Wave Pool, Lemoore, CA. Photo: Glaser
John Florence, Kelly Slater's Wave Pool, Lemoore, CA. Photo: Glaser

The Weekly Grit: Surf Ranch’s Secret Formula Revealed

Now we can all build our own Surf Ranch. It's so simple!

Would you permit me to be honest with you for just one moment? A little real talk? I am neither a scientist nor mathematically inclined. If doctors were allowed to study my brain they would discover synapses coated with bourbon firing vague memories borrowed from Sex and the City episodes (Chas Smith playing the role of Carrie Bradshaw, of course). If they peered deeper, they would stumble upon an above average Mark-Occhilupo-singing-karaoke impression. Nowhere would they find "science" or "math."

And so it was with fear and trembling that I held a worn manila envelope delivered anonymously to my doorstep late last night emblazoned with the words "Surface Gravity Wave Generator."

Should I open? "Surface Gravity Wave Generator" felt like science and math words. They could only send me into a paroxysm of mass confusion. But "Wave." I am a surf journalist, no? Bound by duty to plumb the depths of our shared pastime?

I took a deep breath, ripped the top open, peered inside and there it was. The entire patent for Kelly Slater and Adam Fincham's wave generating machine, along with the secret formula for perfect waves.

All of it.

I read a few paragraphs:

In preferred implementations, the wave pools described herein use one or more foils for generating waves of a desired surfability. The foils are shaped for generating waves in supercritical flow, i.e. the foils move faster than the speed of the generated waves. The speed of a wave in shallow water (when the water depth is comparable to the wave length) can be represented by VW:

VW=√{square root over (g(ho+))} where g is the force of gravity, and ho is the depth of the water and A in the wave amplitude. Supercriticality can be represented by the Froude number (Fr), in which a number greater than 1 is supercritical, and a number less than 1 is subcritical: Fr=VF/VW, where VF is the velocity of the foil relative to the water.

The foils are adapted to propagate the wave away from a leading portion of the foil as the water and foil move relative against each other, and to achieve the most direct transfer of mechanical energy to the wave from that movement. In this manner, ideal swells are formed immediately adjacent to the leading portion of the foil. The foils are usually optimized for generating the largest possible swell height for a given water depth, but in some configurations it may be desirable to generate smaller swells.

The proposed procedure relies on matching the displacement imparted by the foil at each location to the natural displacement field of the wave. For a fixed location through which the foil will pass P, if we let the direction normal to the foil be x and the thickness of the part of the foil currently at P be X(t).

And my head began to pound. Ache. I stumbled to the kitchen and poured a tall Pappy Van Winkle even though it was only ten in the morning. I had to drown the supercritical and the subcritical but then I stopped.

Everything I needed for my own Surf Ranch was in that envelope. Once, when I was twelve, I built a Lego TIE fighter and got it, like, 90 percent right. Maybe 80 percent, but close enough. How different can building a surface gravity wave generator be?

I am now standing in my backyard with a shovel and tape measure. I am going to build Surf Ranch but call it Surf Corral so I don't get sued.

Wanna come over and help?

[Editor’s Note: The Weekly Grit is a trash fire of rumors, opinions and indulgence by BeachGrit founders Chas Smith and Derek Rielly. Their views do not reflect SURFER’s, although we do find them very entertaining.]