It used to be that America's Cup campaigns began in late spring and ended in September, like a nice summer love.

Along came Dennis Conner, who is not the romantic type. Conner bought a boat and built another. Then he went about building a temporary family to keep his two-boat world afloat for a year and a half, instead of just a summer.

Now it's September. One of the two dozen people in that family says a strange sadness is descending.

On the brink of achieving the great goal that has kept them together, the Freedom people are dreading their impending dispersal.

Some time next week, assuming no hurricane, the 1980 America's Cup races will be over. The Freedom crew and their counterparts on Freedom's trial-horse boat, Enterprise, will go separate ways, back to real life after sharing a dream world.

What is real life to a 12-meter sailor?

For the men aboard Freedom it's some form of sailing in almost every instance. While the America's Cup is nominally amateur sport, and while the people who play the 12-meter game are not supposed to be paid for their services, few stand to lose in the long run from their participation. f

Take Dennis Durgan, for example, the tatician aboard Freedom. His wife, Trish, decribes him as a 27-year-old "untitled executive" with a marine supply outfit called Sparcraft in Irvine, Calif.

The bleached blond durgan sells masts and other racing equipment for big ocean racers.

Says Durgan, "This business (racing) goes hand in hand with my business. I've had a very successful year back here, using the telephone and personal contacts.

"There's so much traffic through Newport in the summer. All the big boats are passing through for the Bermuda Race and Block Island Week and the Onion Patch series. I wouldn't say it's helped my business. But it hasn't hurt, either."

Durgan is part of what's called the afterguard on a 12-meter boat -- the brains that stay at the controls in the stern and tell the others how to make the boat go fast. Others in Freedom's afterguard are Conner, navigator Halsey Herreshoff and sail trimmer John Marshall.

While Conner keeps his business dealings quite separate from sailing -- he runs a drapry manufacturing outfit in Calfornia -- the others are locked tight into the heart of the sailing world Herreshoff, 43, is the old man on the boat. His business is naval architecture sailboat designing and building.

Herreshoff speaks with the flat New England accent of honest toilers. His home and business are 10 miles from Newport in Bristol, where he also runs the Herreshoff family museum.

"I'm able to keep things going with the business by being so close to home," said Herreshoff "I can either supervise projects to keep them going or tell my customers they'll just have to wait until the Cup is over." Marshall, 38, is president of North Sails. Most of the racing sails on Freedom are North's and he oversees their design.

Marshall's job in real life is largely to sail aboard big, fast yachts with large sail inventories, to analyze sail problems and induce boat owners to buy North racing sails. As a crewman on Freedom he's doing what he ususally does. There isn't a private yacht around that can afford to buy sails the way a 12-meter campaign does.

Forward of the afterguard are the drones aboard an America's Cup sailboat -- usually a younger crowd of athletic types whose jobs involve more physical effort and peril.

On Freedom, to a man, these posts are held by people whose lives revolve around sailboats and sailing.

Some don't know where they'll turn after the Cup series ends.

Says Rives Potts, who was drafted into the Freedom campaign from a job building boats at Derecktor's Yard in Mamaroneck, N.Y., "I haven't really had time to think about it. I suppose I'll get into the boat business again in some way. That's where the money is."

Potts is 31. He's the strongest and most athletic of Freedom's crewmen.

He holds a master's degree in business from the University of Virginia. He's married. He has been with Freedom for a year and a half, getting room and board and his laundry taken care of. He says jokingly that his goal in life is to be a tugboat captain. In a week he'll be unemployed. He doesn't even know where he's going to live.

Likewise Bobbie Campbell, 22, a mastman on the Freedom. "I've been on her since day one," said Campbell "Maybe when it's over I'll go back to college. I don't know."

Campbell actually has a place to go. His profession is what's politely called "professional captian" of racing sailboats. There are other, unkinder names, like boat bum. He was running the yacht Acadia when Conner came along with an offer. When Freedom is done here, he says, he will take a job running Kialoa, another huge ocean racer.

Lex Gahagan, bowman, gave up his job running the racer Obsession to join Freedom a year ago. He has a degree in geography from Middlebury College in Vermont. Next month he'll put his geographic skills to use in an ocean race off Mazatlan, Mexico. In the winter he'll race the Southern Ocean Racing Circuit in Florida. Between races he'll be picking through "a lot of offers" to run other racing sailboats for their wealthy owners.

Early in the summer Jack Sutphen, one of the older, principals in the Freedom/Enterprise syndicate, said the crewmen of the two boats were "at that wonderful age when they're between school and career and they can do what they want without worrying about fouling up their lives."

It turns out the actual average age of the Freedom crew is 31, which puts it a little over that happy never-never age of no responsibilities.

And just about the right age to get sentimental. "Sure, it's a little like a family breaking up," said Herreshoff the morning Freedom prepared to push off for race two of the final Cup series against Australia.

"We've sailed so much and been through so many races together that we've come to know each other very well.

"This is the greatest thing to do, you know -- to be in an organization where enough time and energy is spent to do things right for a change."

That Freedom has done it right is indisputable. She has spent, by Herreshoff's calculations, three times as much time practicing as Courageous did in 1974.

In the process she set standards of intensity and professionalism for future 12-meter campaigns and sailors. It's not a summer love anymore.

The profile of the Freedom crew, starting from bow and ending at the stern:

Alexis (Lex) Gahagan, 24, bowman, of Oyster Bay, N.Y. A professional boat captain before Freedom, his job on the yacht is judging tactics and distances at the start and handling spinnaker and headsail sets during racing.

Robert Campbell, 22, mastman, of Marblehead, Mass. Professional boat captain before Freedom, his job is to supervise halyards and other mast lines and work with Gahagan on the foredeck.

Donald Kohlmann, 30, of Alameda, Calif. Free-lance sailboat rigger before joining Freedom; plans to return to that line of work. His job is pitman, hauling and storing sails and equipment below decks and helping out on deck when needed.

A. Rives Potts Jr., 31, of Richmond, Va. Boat builder before Freedom, future plans uncertain. He is a grinder, operating a winch used to trim sails, the most physically demanding job on a 12-meter.

Kyle Smith, 25, of New Orleans. Worked in family's marine diesel equipment company before Freedom and intends to go back. Also a grinder.

Thomas Whidden, 32, of Essex, Conn. President of Sobstad sails; job aboard Freedom is tailer, meaning he tells the grinders how far to trim the jibs; also helps in designing and analyzing sails aboard Freedom. Was three times Eastern Finn champion, Canadian national Finn and Sunfish Champion. t

Jonathan Wright, 32, of Rosemont, Pa. Runs a marine supply business in Pennsylvania. A tailer aboard Freedom, he was 1971 college sailor of the year and crewed on Courageous, 1974, and Independence, 1977.

John Marshall, 38, of Addison, Maine. President of North Sails. He is mainsail trimmer and has charge of Freedom's overall sail inventory of more than 80 sails. Bronze medal winner in 1972 Olympics and sailed on Intrepid, 1974, and Enterprise, 1977.

Halsey Herreshoff, 43, of Bristol, R.I. Naval architect who designs and builds boats. Veteran 12-meter racer who is navigator aboard Freedom. Sailed on 12-meters Columbia, 1958; American Eagle, 1964; courageous, 1974; Enterprise, 1977.

Dennis Durgan, 27, of Newport Beach, Calif. Executive with Sparcraft marine equipment company. He is Freedom's tactician, assisting skipper Dennis Conner.

Dennis Conner, 38, of San Diego.Runs a drapery business when he isn't sailing. He sails some 300 days a year. Conner is three-time Southern Ocean Racing Circuit champion, twice Star Class world champion and the tactical and managerial brains behind the Freedom campaign.