Skating the deep end? Old school. Today’s skaters are pushing their limits on stairs, handrails and anything else they can think of.

Riding on a prayer and four spinning wheels, Tony Alva bombs a hill into traffic, perfectly timing his run into an intersection as the light turns green. Next comes Jay Adams, dropping from his roof into an alley before ramping up and riding over a parked car. Later, they’ll join Stacy Peralta -- to skitch off the back of a bus and skate the smooth, curving concrete of drought-drained swimming pools.

This is all within the first half-hour of “Lords of Dogtown,” the skateboard film that opens Friday. In this fictionalized version of Peralta’s 2001 documentary “Dogtown and Z-Boys,” the Venice Beach skater gromets are played by actors, but it doesn’t diminish the power of the Dogtown style -- a style that gave birth to modern skateboarding. Watching Alva, Adams and Peralta skate is like watching Van Gogh learn to paint. In the ‘70s, they not only transformed the relatively tame activity of skateboarding into an athletic, edgy sport but also elevated it to an art.

As exciting and groundbreaking as they are to watch on screen, however, the Z-Boys reflect a bygone era in skateboarding -- when empty pools were the proving ground and reps formed around flow, connectivity and style. Thirty years later, who skates, what they skate, as well as how, where and when, has done a kick flip. For a new, multicultural generation, the sport’s gone airborne and completely turned around, leaving its surfer roots to spin tricks over stairs -- and, with its enduring rebel spirit, generating controversy along the way.

“You look at other traditional sports, and they’re still playing basketball on the same court as 75 years ago,” said Jim Fitzpatrick, vice president of USA Skateboarding, the sport’s national governing body. “They’re still playing baseball on diamonds that are pretty much the same dimension. And then you look at skateboarding, and it’s changed.”

Radically.

For starters, the sport itself is less about style and consistency now than technicality, tenacity and grit. It’s about ingenuity and guts coupled with a lot of luck and skill. And it doesn’t at all follow the model of traditional sports. Racking up sponsors and going pro isn’t accomplished through contests but video clips. Careers are made in seconds -- about as long as it takes to do a nollie caballero kick flip. (That is, to jump into the air off the board’s front end and rotate your body 360 degrees while flipping the board once in midair.)

That’s a big reason why venue is important to skaters. These days, many say it isn’t about empty backyard pools. It isn’t about skate parks, which cities have built to provide a legal, supervised alternative to the streets. It isn’t about those U-shaped “vert” ramps you see at the X Games or Tony Hawk. It’s about the endless opportunities that urban landscapes provide for improving riders’ skills, despite (or maybe because of) the hazards and legalities.

“One of the reasons we searched so many pools in the ‘70s is because every pool was different. Every pool offered a challenge. Every pool offered a way for you to develop better,” said Peralta, now 47. “Your talent became infinitely better with the more places you rode.”

That remains the case. It’s just the places that have changed. Today, skaters will ride anything (lunch tables, electric utility boxes, public art sculptures), anywhere (schools, churches, dental offices), and they will do it whenever they can, even if it means they’ll be chased by police, security guards and teachers.

“The mainstream thinks that every skateboarder aspires to be in the X Games,” pro skater Rob Dyrdek said. “No one can fathom that the top 200 pro street skaters run from cops on the weekends and use a generator and lights to light up a handrail at 2 in the morning to get a trick that’s going to be in an advertisement that will be shown around the world.”

According to a 2004 survey from Board-Trac, an Orange County firm that follows the skateboarding industry, 73% of the country’s 11.9 million skaters prefer skating open pavement to skate parks, ramps, pools and drainage ditches. Street elements are, after all, everywhere. Skaters don’t need to travel far to find them. They don’t usually wear safety gear, as many skate parks require. And they aren’t restricted to certain hours, though skaters normally time their street riding to avoid run-ins with authorities.

“People think we’re dirty, troublemakers, bums. They think all we do is stay out on the streets and go home and don’t take showers. They think we’re stupid for doing the stuff we do, like go off stairs,” said Jade Jaber, a 14-year-old who skates in Glendale. “They think we’re crazy.”

Adds Jomari Santiago, 13: “All we’re doing is just trying to have fun.”

Despite its popularity, skateboarding remains one of the most hotly debated cultural phenomenons of our time. To skaters, it’s about doing what they love and getting good enough to go pro or at least win sponsorships that will get them free gear from shoe and board companies. The stairs, rails and ledges they skate are merely the tools of the trade. Skaters are judged by how high, far, fast and inventively they ride them. Street elements aren’t just what they want to skate, it’s what they have to skate to get to the next level, they say. It’s their opportunity to get a piece of the $5.2-billion skateboard industry for themselves. Whatever property is wrecked in the process isn’t malicious, they say; it’s just an after-effect of what they do.

But to property owners and law enforcement, skaters are a danger, a nuisance, a liability. They are rats on wheels, an accident waiting to happen. They intimidate pedestrians, make a lot of noise and cost a lot of money defacing everything they grind, slide and skate.

In California, skaters have state and municipal laws to contend with. In the city of Los Angeles, for example, skating on streets and sidewalks is not illegal, per se, but a boarder can be ticketed if signs are posted prohibiting skating. State law requires minors to wear helmets while skateboarding in any public place; violators are subject to a $25 fine. Depending on the circumstances, street skaters also can be cited for trespassing, disturbing the peace and vandalism.

Many cities have ordinances prohibiting skaters from riding in business districts or at schools, yet the latter two are often magnets for skaters. When business is done for the day, skaters hear the call of the wide, unpopulated swaths of concrete that serve as irresistible speedways for flying leaps over stairs, flipping tricks over rails and jumping “gaps” from one paved surface to another. There are concrete planters and benches for grinding, banked walls for launching and picnic tables for ramps and obstacles.

“All it takes is for one place to get built and found and the entire skate community has heard about it and is going to skate it,” Dyrdek said. “No police officer could ever fathom that. They say, ‘Why don’t you go down to the Block [skate park in Orange County]?’ They think you could go to a skate park and do the same thing. There’s a huge disconnect.”

In L.A. there are a number of legendary “skate spots,” as they are known -- the banked walls at Paul Revere Charter Middle School in L.A., the ledges at the West L.A. courthouse, the flight of 16 stairs with a rail behind Hollywood High. Skated by pros and featured in videos, magazines and websites, they are Mecca not only for local skaters but also skaters worldwide, some of whom come to skate it, others just to see it.

“I don’t skate giant handrails or anything, but the first time I was walking around Hollywood after I moved here, it was one of the things I had to see,” said longtime amateur skater John Sahas, 33, who recently relocated from the Northeast to Woodland Hills. “Oh. Hollywood High. I’ve got to go check out that rail and see how it looks in person. Seeing it in front of you really put it in perspective.”

News of these skate spots spreads like wildfire once they are discovered, mostly by word of mouth. Most of them are shut down, or skate-proofed, just as quickly. Former hot spots that have been made unskateable (or “knobbed”), with metal ties placed around the handrails and concrete bumps on ledges and banks, include the corner of Jefferson and Hoover near USC, and the ledges at the intersection of Santa Monica Boulevard and Melrose Avenue.

“You can only skate a hot spot for so long before everybody knows about it and it gets crowded and then all of the sudden there’s a bust and then it gets knobbed,” said Cameron Postforoosh, 28, co-owner of the Westwood skate shop Hot Rod. “Most spots, you go there now, you get 15 minutes. You go there, you turn the video on, and you better go. You’ve got to get your trick when you go to the spot, or you’re wasting time.”

The majority of skateboard videos these days are shot on the street. Street skaters may use skate parks for practice, but it’s in the streets where they film each other skating -- collecting seconds of their best moves on video so they can send them in to potential sponsors.

For many street skaters, skate parks just don’t cut it. There are 46 in L.A. County, 13 in Riverside County and 20 in Orange County. That may sound like a lot, but there are 706,000 skaters in those three counties, according to research firm American Sports Data. And few of the parks are truly reflective of what’s happening at the street level, skaters say. The majority emphasize X Games-style vert skating and Dogtown-era bowls.

The city of Santa Monica’s long-anticipated skate park at Memorial Park, opening June 17, does a better job than most incorporating street elements. There are steps and an authentic handrail imported from nearby Douglas Park, an area popular with skaters. But the street elements don’t reflect the increasingly technical trend. They make up only 40% of the 20,000-square-foot park; the other 60% consists of three, old-school bowls.

“I live five minutes from there. I won’t go there. It’s just not what we as street skaters skate,” Dyrdek said. Next week, the 30-year-old street skate pro and founder of DC Shoes will open the Rob Dyrdek/DC Shoes Skate Plaza in Kettering, Ohio, his hometown. The skate plaza, he says, is different from a skate park in that it’s all about street skating.

In designing his new 27,000-square-foot plaza, Dyrdek showed the drive that propelled him to the sport’s upper echelons. He traveled to his favorite skate spots in L.A. and measured all the rails, steps, benches and ledges. He took pictures. Then he taught himself how to draft, created architectural renderings and compiled them into a 100-page reference book that was used to design the plaza.

Dyrdek was hoping to open a skate plaza in Southern California immediately after opening the park in Ohio, but he hasn’t been able to sell the idea locally.

“I’ve been trying to give away $250,000 somewhere in Southern California for the last three years. From Ventura all the way to the Tijuana border, every city under the sun still can’t fathom the concept,” said Dyrdek, who’s in talks with a company about building plazas privately. “I feel like there’s no hope for California, the place that needs it the most. California just does not remotely embrace the fact that it’s where skateboarding itself was birthed and where 90% of the industry is.”

Dyrdek hopes that once his Ohio park is open it will serve as an understandable model. But one way or the other, it’s also likely that Southern California street skaters will continue what they’ve been doing -- discovering spots and riding them as long as they can before being chased away and moving on to the next place.

“The beautiful thing about skateboarding is that no matter how many places they make to skate legally, there will always be places to skate illegally, and kids will always want to skate illegally,” Peralta said. “That’s what’s fun about it.”

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(BEGIN TEXT OF INFOBOX)

Dogtown gives way to today’s young pups

The one thing unchanged since Tony Alva, Jay Adams and Stacy Peralta rose from the streets of Venice is the thrill of riding four urethane wheels. But in the 30 years since Dogtown reigned, everything else has pretty much done a kick flip -- it’s gone airborne and completely turned around.

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SKATE SPOT

THEN:

Empty swimming pools. “Vert” skating was born when surfer culture collided with the invention of urethane wheels and the drought.

NOW:

Schools, banks, corporate parks -- anywhere there are smooth stretches of concrete, stairs, handrails, benches, banked walls and ledges.

ACCESS ACCESSORY

THEN:

A water pump, used to drain excess water from pools.

NOW:

A generator and lights to light up skate spots at night.

TRICK

THEN:

Carving -- turning the skateboard with all four wheels on the ground.

NOW:

Flips -- turning the board in the air -- in all their multitudinous permutations

SKATEBOARDS

THEN:

Alva and Powell Peralta boards. Tony Alva and Stacy Peralta were skateboarding’s first bona fide superstars. Their pro status was quickly followed with their own lines of boards.

NOW:

Each skating subculture embraces a different brand. Girl is popular with twentysomething artsy skaters, Zero with punk types, Baker with wannabe bad boys.

TOP SKATER

THEN:

Tony Alva, known for big moves and an even bigger ego.

NOW:

Non-skaters know Tony Hawk, but street cred belongs to Paul Rodriguez, Guy Mariano, Gino Ianucci and, above, Reese Forbes.

-- Susan Carpenter