They sit in their aluminium chairs on the old hotel and apartment porches in all but the worst weather, staving off the time when they must go back to their damp efficiencies and hot plates and night-time memories of other days.

For these elderly, mostly European-born Jews who dominate South Beach, the southern-most dozen or so blocks of Miami Beach, there is the knowledge that this will be their last home.

Some face this querulously, but for many more, just being alive is a social event. They fill their days with free concerts and movies and dances and chess and pinochle and kibitzing and that great joy of being Yiddish, arguing.

One man is asked what he likes most about South Beach. "Well," he said, "The dences. I like the dences." He is 90.

This colorful and tumultuous ghetto is now being threatened with extinction by a multimillion-dollar redevelopment project that would create a man's paradise out of the decaying streets and 1930s apartments the elderly call home.

The same architects who designed San Francisco's Giardelli Square have created hotels, condominiums, marinas, canals, theaters, convention centers and "Wet World," a recreation facility that includes flume rides, scuba diving and rafting. It is considered the largest redevelopment and relocation project attempted in one location - covering 255 acres along Ocean Drive, Collins Avenue and Washington Avenue between First and Sixth streets.

That world is now but a few inches high in model form, but the Miami Beach redevelopment board, actively wooing prospective builders and developers, plans to launch the $500 million project next spring - simultaneously moving some 200 of the 6,000 residents that must eventually be relocated.

The rich businessmen pushing the redevelopment are sensitive, close to paranoid one said, about the criticism heaped on them for obliterating one of the nation's most distinct elderly enclaves. Over and over, they say they plan to spend $40 million to move residents up the beach a few blocks to apartments "better than they have now," or into the 750 units earmarked for elderly people in the new project.

The agency says only half the residents expressed a desire to remain in the area - but during several days of wandering the streets and parks by the sea, it is hard to find anyone who wants to move.

"We will not go! They are trying to push us into the sea.I am staying in my chair. They will have to drag me. We can't march, but we can sit! We will sit in the streets," said one man, echoing the thoughts of many, in a torrent of broken English, as soon as redevelopment is mentioned. He sat on the whitewashed apartment porch at First and Ocean Drive; white hair combed back from high cheekbones, his senior citizenry masked by a patina of perpetual tan. He wore slippers and trousers too big, bunched and notched with an old belt at the waist.

He brushed the air in front of him with a gnarled hand. "All this will be canals. Do we need canals?They stink in Venice. They stink all over the world. At one meeting I protested and they said, 'give young people a chance,' and I said, 'What do you expect us to do? Drop dead? Wait until I die.'''

There is a tendency to think of Miami Beach as a monolithic cluster of the super-rich, living in those 20-story gleaming white condominiums that forever block the sun on Collins Avenue.

But this other world, a few blocks south, teems with character and characters, seedy though their living conditions can be.

The problems Miami faces in uprooting its elderly - a group described by one civic leader ad "spending their active, useful lives up north and now getting a free ride for $150 a month rent on some of the finest property in the world" - in part foreshadows the problems that will be faced across this land as our population grows older.

The elderly are already a strong political force in many senior citizen communities. They have no jobs or family to keep them from the daily pursuit of finding out what their politicians are - or are not - doing for them. And the statistics show a startling population shift already underway, as fewer children are being born. By the year 2,000, the median age of an American will be around 42, according to some statistics. Last year, the median age was 29.4 years old.

In the future, growing numbers of retirees are expected to boost migration to such favorite sunbelt states as Florida and Arizona, but the impact of a fading youth culture will be felt throughout the nation. Some sociologists envision a war between the ages over conflicting needs that will make past generation gaps seems idyllic.

In South Miami Beach, that conflict is much in evidence as the elderly, resistant aa barnacles on a boat, fight to stay.

The enclave houses a unique and dying breed. They huddled in Manhattan's Lower East Side, worked in sweat shops at the turn of the century, after fleeing Russia's pogroms and persecutions. Steeped in the philosophy of the social revolution, they fought to organize union shops here in the '20s, when it was truly a life-and-death struggle. Many are activists still, protesting the neutron bomb, fighting for social issues, supporting liberal candidates. The elderly of tomorrow will never be quite the same.

Harry Korsen, in his 80s, remembers his childhood in a Russian village - racing down streets as he was taunted with cries of "Yid, Yid . . ." and living in a house with a straw roof. "For warmth, the little ones would lie on top of the brick ovens." Korsen worked his way up in a Manhattan restaurant to manager before retiring, and was a Russian interpreter during World War II. Now he writes senators and pushes local candidates to spend money on the poor and for national health. "We should stop wasting money in preparing for wars. I'm interested in the human race. I don't want to see it destroyed." "We, at Least, Speak English"

Such peaceful sentiments are not always expressed for one's neighbor on the teeming South Beach streets, where contentiousness seems the norm. In the elevator of one of the apartment buildings, one man in his early 70s, full of good morning cheer, holds the door open for an old bent man in his 80s. "Good morning!" beams the first as they ride up. The second looks up and glowers, "Who are you? Do you know me?I don't know you. What you say good morning for?" The door opens and the first man gets out, now angry. As the door closes he says, "Acchhhhh, have a lousy morning."

At South Maimi's crossroads - Collins Avenue and Lincoln Road - the drug stores hawk free glaucoma tests and blood pressure checks for $1. The shrill siren sounds of ambulances send daily messages as the elderly are rushed to hospitals. Some apartments organize "oxygen squads" to help tenants in emergencies.

Wolfies, with it's "world famous" flashing sign, a haven for lox and bagel fanciers, is a part of changing times. Some signs are now in Yiddish . . . and Spanish, in a world where English has now become a third language.

Outside the restaurant, a vendor hawks the "Jewish Forward" and a Spanish newspaper. Inside Wolfies, two customers speak in Spanish, another in Yiddish as a garrulous waitress throws up her hands. "I got all kindsa problems. I don't know which to solve foist."

On Washinton Avenue, the main shopping center, kosher stuffed kishke and schmalz herring coexist with arroz con pollo. There are "Se Habla Espanol" signs in kosher butcher shops.

Most of the Cubans are younger and work in South Miami Beach, speaking Spanish to one another over the heads of elderly Jews. There is contempt in their eyes and little attempt to commingle.

One women who refused to give her name - "There are too many Yentas around who will want to know my business" - was asked what she thought about the Cubans moving into her world.

"Well. I'll tell you. It's a free country. They don't do any harm. Who am I to say anything? I won't say one bad thing about them. . . . But . . ." Ten minutes later, she was still going on - they didn't bother to learn English, they didn't teach it to their children, they didn't keep their kitchens clean.

"And . . .," she says, jabbing a bony finger in her listener's chest for emphasis. "They are so arrogant! One clerk had the nerve to say to me. 'Why don't you speak Spanish?' I told her, 'Listen, young lady, I am in the Americas. Here I speak the language of the country. When I go to Cuba, which, God willing will be never, then I will speak Spanish!'" She moves on muttering. "Ve may say ven, vat, vy and vhere - but it's English!" Sometimes, They Even Buy

In the Thrifty Supermarket, a social center as well as a drag strip for gocart warfare, the elderly move through - inspecting, touching, poking and sometimes buying the merchandise. A woman was once heard to say to a butcher there, "May you have an injury that is not covered by workmen's compensation." When it rains, shopping is an all-day, battle-filled adventure.

One day a man in baggy Bermudas, "Miami Beach" stitched in bright-colored beads on his belt, pored over the lettuce for 10 minutes. He offered passersby his view, "That is a good one. That is not." A major anxiety is felt in front of the meat counter, as customers holding numbers seem to live in terror of not getting waited on in turn.

"Number 28!" bellows the butcher. "Here, here," shouts an old man, pushing forward, "that's my numbah." Thrifty deals often in single items for their fixed income clientele. The man with number 28 buys one herring in our cream for 49 cents. "We Are Not Dead"

Nina Rosenburg Yardeini, in her 70s, sewed in a sweat shop all day for $5 a week, at age 14, when she came to America from Russia. She studied bookkeeping at night, took up literature and met her first husband, "a brilliant student, a fighter for the unions."

Today, she lives with her second husband, a cantor, in one of the better apartment buildings that will remain when the new South Miami Beach is developed. From her balcony, she sees the long expanse of beach, far better than the pathetic strip of eroded beach in front of $75-a-day hotels further north.

"I know why they want this land, but I think it is pathetic, what will happen to some of the people here. The Jewish Community Center is like a temple to them. That will be a canal." The redevelopment board has computerized the old people into neat little rows of statistics, by age (13 percent are over 80, the median age is close to 70). They are referred to as living in a "target area."

Brochures abound in sociological gobbledygook: "The plan has evolved from a mult-disciplinary analysis of the physical, social, environmental," factors "affecting redevelopment."

The developers say, 'We are putting people in this job whose whole specialization is moving people. And we are paying them for moving. If we see a man on the list who is 72 years old, say, we will pay him money for the rest of his life span. We expect him to live eight years. Over the rest of his life, he will be paid $20,000."

Such computerized caring is far removed from the broken English spoken by those who actually live there.

"These people made a contribution to our society," says Yardeini. "They should not be thrown in holes and forgotten. They have every Saturday night a dance and they have reading circles." Her husband adds softly, "And they fall in love." She shrugs. "That's all right.Two years we are married. Maybe for people of 70 it's stupid. But we are not dead."

One man stops his pinochle game long enough to offer, "You heard about the law in the sunshine? There is no law; only crooks. Politicans permit them to steal our homes. To sell to private corporations, which is not in the U.S. Constitution. And that Stephen Muss! He's got half the beach now already. What does he need with it all? He should drop dead before the project begins." Borsht Circuit Comedy

Stephen Muss, chairman of the Miami Beach redevelopment board, is the centerpiece of the project. The largest single taxpayer on the beach. Muss lives in an ornate duplex in one of his five Seacoast Towers high-rises on Collins Avenue. Muss purchased the Fountainbleau Hotel in March and he turns down requests for interviews "from everybody, New York Times, People magazine, you name it" because, "Honey, I am paranoid about the press. One 'friend' wrote that with my manicured fingernails and dress that I was reminiscent of the Mafia, or some such crap." Muss, 50, is a huge man whose mane of curly hair looks more sculpted than cut.He goes to board meetings with an orange shirt unbuttoned halfway to his naval, smokes long cigars, wears one gold bracelet. The first adjective used to describe him, by friend and foe, is abrasive. The second is hard-working. Muss inherited the multimillion-dollar business started in New York by his father. "The company proudly boasts that over 125,000 people live in Muss-built homes," one brochure boasts. The family moved to Miami 15 years ago to erect their concrete jungle on Collins Avenue, just north of the Fountain-bleau.

Some apartments at the Seacoast Towers rent for $700 per month. "Everything," as one elderly resident, three miles south on his dilapidated porch, put it, "is very fency-dency."

The lobbies with marble columns, corridors and staircases, cascading chandeliers, gilt, and indoor Japanese gardens with fake cherry trees, look like the palaces of some Roman emperor whose interior decorator ran amok. Massive gold doorknobs, in the shape of fish, open the doors to a theater that features musicals and Borsht circuit comedians.

Women residents wear Ultrasuede pantsuits and alligator shoes; their husbands wear baggy-sleeved golf sweaters, gold chains and white loafers.

At board meetings, Muss cracks jokes, but he gets a bit impatient when a member of the audience starts in about the plight of businessmen in South Beach who will have to move.

"We've been very careful, and in our judgment, very generous." says Muss.

"We'll never be able to solve the problem in totality."

It is indeed a more complex problem than whether the elderly poor are being pushed off the beach.An outsider in their midst ends up feeling that both sides are right . . . and that both sides are wrong. "Can I Help You Anyway?"

Miami Beach was a garish, overbuilt, dying sunland five years ago following the building boom crash. Today it is being revitalized, often with international investments - from Canadian dollars to Venezuelan petrobucks, as the rich grow increasingly nervous about the economies of their own countries.

Miami City civic leaders and politicians see a gleaming new South Beach "Riviera" as necessary and vital, now that most of the beach has been used up. "These old people are sitting on some of the lushest real estate in the world, paying nothing," says one local businessman. Irwin Sawitz, manager of Joe's Stone Crabs and vice chairman of the redevelopment committee says, "Their productuve years were spent up north; I feel their burden to a city such as ours is disproportionate to their ability to participate financially."

On Saturday night, the Rolls Royces still glide through the streets of South Beach to queue up in front of Joe's - begun in 1931 by Sawitz's father inlaw, Jessie Weiss.

Weiss has known the famous - Louis B. Mayer, Jack Benny, William Powell. Clark Gable J. Edgar Hoover and Al Capone both used to eat at Joe's and Weiss would joke to Hoover, "half the guys you've been looking for are over there across the room."

One day recently in his office as chairman of the Tourist Agency. Weiss took a call: "How do you feel Boobie? When do you open? You're staying at the Fountainbleau? I'll give you a ring. You're coming early for dinner? Fine. I'll see you tonight and we'll kibitz. Can I help you anyway? Fine. See you." It was Joel Gray, a "great guy."

Weiss, 70, is a warm and affable fixture immortalized years ago in a Damon Runyon column. He has spent 65 years of his life in Miami, knew it when it was a swamp and then a 1920s Gatsby playground for men such as automobile entrepreneurs Carl Fischer and partner Jim Allison, who built the Indianapolis speedway. They had yachts the size of battleships and mammoth estates which were torn down to make way for hotels in the late '30s. These hotels became World War II Army barracks. After the war, in the era of "this year's hotel" the Fountainbleau and Eden Roc became the hulking white palaces up the beach and the 1930s hotels became havens for the elderly who fled the winters of Far Rockaway and Chicago and Manhattan's East Side.

Those old buildings surrounding Joe's Stone Crabs will eventually come down. Joe's, declared a historical landmark, will stay.

Weiss says, "Some of these people could afford better places, but they feel comfortable together. I can't tell you the times the fire department has arrived and found thousands of dollars under the mattresses. And the savings and loans do a terrific business. These people will be moved to better places. Anything that will rehabilitate Miami Beach will do nothing but good." Slums in the Sun

It is a Sunday and they sit row upon row on Ninth Avenue by the sea, old women with parasols and little fluffy pink hats, men in baggy bermudas and, sometimes yarmulkes. There is a small outdoor stage with one mike, an American flag and the blue and white Star-of-David Israeli flag. A line of elderly people sit beside the stage, waiting their turn for the mike.

Vic Hindin, now 74, sings off key, "Every man a daring warrior . . . Always first and never tiring," then softer, but still off key, "Shalom." Slowly, the crowd takes up the familiar phrase, "Shalom, shalom. . . ." A woman with hair dyed patent-leather black, in hose rolled down to her knees and bermudas, speaks in Yiddish to a friend. A man does an odd little dance, twirling, twirling on the sidewalk to every song, ignored by most. After each number, no matter how terrible, he gives a resounding, "verrry good!"

Hindin bows to the applause, then returns to the audience. "I used to sew upholstery. I learned the songs with a vaudeville group in Far Rockaway. We were very good."

At night, for a quarter per person, there is dancing in the pavillion; the cha-cha, the tango, the foxtrot; silver heads bowing and weaving in the moonlight. One old woman, in gold slippers, moves and minces by herself to "Hello Dolly," giving it a high kick or two.

Another woman turns to a friend and says. "Who does she think she is? She must've been in burlesque once. Look at her, at her age!" Her friend, in a more tolerant mood, says "Down here, age is only your number."

For some, life in South Beach is slums in the sun. On the porch of one hotel across from the park, badly in need of plant, sit five residents. Their complaints pour out. "They gouge us with rent." "They take the hide off us . . . I have no stove, just a hot plate."

A woman with snow white hair and small good pierced earrings, is writing a beseeching letter in a spider scrawl. "In such a family as large as ours, certainly someone could afford a place for her. . . ."

She is in her 80s, fled the 1905 Russian pogroms with her family, speaks Russian, Ukrainian, Yiddish, English, Spanish. "They give us food, five days a week. The bus comes to pick us up for the noon meal. The food is so bad half of it goes in the garbage can. Last week we had what was supposed to be fish. It was shaped like Matzoh balls but was hard as a rock." She starts to cry, "I wrote them a note. 'This fish is out of this world. It should have stayed there.'"

Her friend says, "I call seven places to get a free ride for the doctor. I get no satisfaction, and I just got a new pacemaker. . . ."

They are afraid to give their names, desperately afraid they will be kicked out of their apartments. The woman with the new pacemaker slowly leads the way to a creaking elevator and to her efficiency. Manishwitz Tam Tam crackers on the table, a bed, a hot plate, a curtain dividing the toilet and sink, Clorox bottle under the sink, faded pictures of family on the wall.

"I tell you, I could lie up here for days and nobody would check. I was a practical nurse. I used to baby-sit. Not just one night, but three weeks, four weeks at a time. I worked in some gorgeous estates." Her voice trails off.

Her son is divorced. "He can't help me that much. He has his own problems. My Social Security is $249.90 a month. My rent is $183." She has about $16.00 a week left over. When she got sick and couldn't get any transportation, it cost $4.00 to go to the hospital by cab.

"I always said I was going to grow old gracefully. . . ." The tears flow down her deeply wrinkled, deeply tanned cheeks. "But when things hit you in the face, you can't help it." "A Regular Garden of Eden"

Outside, the sun is beginning to set. In the park, the stage is now empty of its self-styled performers. Four men play pinochle on a flat wooden board laced with rubber bands to slip cards under to keep them from blowing in the wind. They answer questions without missing a play.

"With the development, this park will be gone. Our world will be gone."

The extra stipend to relocate, the possibility of leaving crowded and expensive apartments, of moving to a place safer from crime, means little to them right now.

As the sun goes down, hundreds of South Miami Beach residents pick up their collapsible aluminum chairs and slowly, ever so slowly, move out of the park.

One lone man sits hunched over an instrument on a park bench. As he plays, the air is filled with the soft sounds of a balalaika. . . .

"Would you look?" asks an Old woman with a thick European accent. "A regular Garden of Eden."