LONG BEACH ISLAND, N.J. - This is ground zero in Steve Chernoski's debate, his life's mission, his quixotic quest, his third documentary, all of which seek to settle once and for all this pressing question:

Where does North Jersey end and South Jersey begin?

Chernoski's a man haunted and obsessed. Counties, criteria, catch phrases spill out of his mouth.

He's at the end of a yearlong mission with two Russian-born filmmakers (and they know from border disputes) in which he has traveled to every one of 21 counties in Jersey to ask people to draw the line separating south from north.

Everyone has a different idea. Chernoski himself has 13 theories.

Is it merely geography? (Draw the line at Route 195 or, as some northerners say, at the Driscoll Bridge, wherever that is.) Is it culture? (WaWa or no WaWa?) Sports? (Eagles or Giants?) Food? (Jimmies or sprinkles? Hoagies or heros? Italian or water?) Fashion? (Flip flops or stilettos?) Language? (Bennies or shoobies?) Beer taps in bars? (Are they covered with a Phillies baseball or a Yankees baseball?)

How about politics? In Tuesday's U.S. Senate primary, Chernoski accurately predicted Lautenberg vs. Andrews results in each of 21 counties. Strikingly, the results nearly exactly followed his Dunkin Donuts theory, see below.

And, is there a place where South definitively gives way to North?

And is that place where Chernoski is standing, smack in the middle of Long Beach Island?

Or, is Long Beach Island definitively North or South?

"People are very confused here, even though geography points south," says Chernoski, 30, on location in the middle of disputed LBI. "There's a lot of ambiguity. The question is, is it culturally south?"

When you live in parts of undisputed South Jersey, say, Cherry Hill, the question may seem obvious. LBI, despite being above the Atlantic City Expressway, despite the influx of New Yorkers, despite the Giants jerseys, despite being called a poor man's Hamptons, is South Jersey.

But a recent guide book to the South Jersey shore drew the line at Brigantine and South, leaving out LBI, and its author, Jen Miller, who is also a consultant on the film, has had to answer to that everywhere she goes, at least south of Surf City. Her theory involves roads and train, as in Philly goes down the shore, not across the shore. (Sure, Jen. Just remember, in Philly, LBI is South Jersey. Have you seen the traffic on Route 72?)

When you're from North Jersey, it can be equally simple, says Chernoski. Anything with a beach is South Jersey. "They'd laugh at the whole discussion (of whether LBI is north or south)," he says. "In North Jersey, the entire beach is South Jersey, from Sandy Hook on down. If you see sand, it's South Jersey.

But for Chernoski, with his shock of black hair and fast-talking enthusiasm, it's not so simple.

This is because Chernoski, a school teacher now, grew up in disputed Mercer County, confused. He rooted for the Eagles (South). He rooted for the Jersey Devils (North).

Am I South Jersey? Am I North Jersey? Am I Philly? Am I New York? He lay awake at night wondering.

One time, in 1988, he wore his Devils Jersey to a Phillies game, and had his loyalties questioned from all sides.

He wondered, like a male Carrie Bradshaw whose obsession is geography, is there such a thing as Central Jersey? Does it have its own culture? Does that solve anything?

Now, Chernoski, along with filmmakers Andre Litvinov and Alena Krutchkova, has developed the main theories, with new ones coming every day. (Dunkin Donuts theory: if you go to Dunkin Donuts and get a box of Joe, if it is an Eagles box, you're in South Jersey; Giants box is North. And the latest suggestion: When you think organized crime, do you think Gambino (north), Scarfo (south) or Soprano (HBO).

The film, to be called, simply, New Jersey: The Movie, has cost about $11,000 so far and is almost complete, with the filmmakers hoping to have showings around New Jersey and to submit it to various film festivals in August.

Cheroski started a blog, www.nsjersey.blogspot.com, in which these pressing issues are discussed and voted on every day. Asbury Park, north or south? (Come on, Steve, that is as North as Hoboken, we're talking Exit 100). Ewing, Chernoski's hometown, North or South? Blog readers voted North. He gets hate mail from Central Jersey people. Springsteen, north or south? (Everyone claims him.)

Complicating things up North is that some Jersey counties (Warren) have parts that border rural Pennsylvania. In other words, they speak hoagie in Warren!

"There's two brand new WaWas in Phillipsburg!" Chernoski notes with the wonder of a scientist on the verge of a breakthrough.

"We're coming up with two (border) lines," he says. "A line that we decided based on our criteria. And a line from our interviews with people in every county that will be averaged by my students."

In the film, the filmmakers also interview people in New York and Philadelphia (the ends of Ben Franklin's famous "barrel tapped at both ends" phrase), to see what they think of New Jersey.

Answer: Not much.

But the shoobies in South Jersey are nicer to the locals than the Bennies in North Jersey, Chernoski says. That's because Shoobies and locals are like cousins in South Jersey, more inbreeding.

Obviously, if your loyalties, and cable package, tend toward Philly, you're going to identify as South Jersey.

And if you talk with a funny accent, obviously, that's North Jersey. Right?

There will forever be anomalies. Some days, Chernoski says, Monmouth and Ocean just don't fit into any consistent theories. And that rodeo town in Salem County, how do you even begin to fit that into South or North, or even comprehend its existence?

Now, about Staten Island.

"I think New York wants to disown Staten Island," says Chernoski. "You can just give it to New Jersey."

Well, it always did seem to people coming from deep South Jersey that you don't get out of North Jersey until you cross over the Verrazano and hit Brooklyn.

Check out the trailer and the debate at www.newjerseythemovie.com and www.nsjersey.blogspot.com.
Contact staff writer Amy S. Rosenberg at 609-823-0453 or arosenberg@phillynews.com. Read and comment on the philly.com shore blog go.philly.com/downashore, where the LBI, north or south, debate has been in full swing.