With the final reading of some of his light verse, noted humorist and satirist Richard Armour could hang up his halo as one of the ship's guardian angels helping passengers battle boredom, and return to his terrestrial turf of Claremont, Calif., about 30 miles east of Los Angeles -- 55 days and 13 lectures later.

Even in the moveyed world of cruising there is an elite elite -- a handful of lecturers, authors, clergy, doctors, artists and baby sitters who get a free ride aboard luxury ships in exchange for some of their expertise.

"I must be the envy of all the rabbis in New York," says Rabbi Dr. Benjamin B. Wykansky of Temple Eman-El in Staten Island, N.Y. After 28 years of cruising to England each summer with the Cunard Line, he was recently invited to be aboard the line's Queen Elizabeth 2 on a scheduled 80-day around-the-world cruise.

"People think cruising is all eating and drinking," complains one veteran cruiser. "It's not -- it's cultural enlightenment."

To that end, druise lines do their best to provide lectures on port cities to be visited, books, finance, oceanography, bridge, arts and many more topics. These are in addition to typical cruise offerings of shuffleboard, swimming, films and live entertainment. "The idea is to provide lightness and light," says Armour of Royal Viking Line's enrichment program.

It's all part of a continuing effort by passenger lines to market and package cruising as a distinct vacation experience -- somewhere between heaven and earth. Indeed, the creation of a seagoing middle kingdom is what has been the salvation of cruise lines.

Just 10 years ago, the future looked bleak for the industry. "In the press there was considerable gloom about passenger ships. The general feeling was that with modern airplanes, ships had reached their end as a transportation system, says Warren S. Titus, president of Royal Viking line and chairman of Cruise Lines International Association.

Today, it is estimated that cruise revenues out of the North American market are a healthy $1.5 billion. Since the early 1970s, with the increasing popularity of seven-day, cruise-fly packages, the number of cruise vacationers has been increasing by upwards of 10 percent annually.

To keep the ships full, the lines rely heavily on repeat passengers. Hence, the attention to making sure cruising is fun.

"The greatest sin on a luxury ship is to allow passengers to get bored," says one lecturer. "The ship has to keep them occupied, entertained, well informed, well fed -- and well lubricated."

Indeed, having a few notables aboard to mix with is an important extra draw.

"It is not an economic consideration," says a spokeswoman of Royal Viking. "It is to provide an intellectual endeavor in addition to Ping-Pong and other activities -- to give as broad a program as we can."

To seek the chosen few, some shipping companies use booking agencies, some word of mouth, others just wait for letters. "We get floods of applicants every year," says one operator of a New Jersey agency.

"One member of the clergy wrote me," recalls one cruise executive, "and said he would include my name in his morning and evening prayers. I bet God is as tired of hearing my name as I am of letters."

Exchange policies vary from line to line. Some deal strictly on an exchange basis -- free passage for the lecturer and spouse. Others negotiate case by case -- the spouse may have to pay passage or the lecturer may receive a fee. The number of such positions depends on the length of the trip -- three weeks or longer.

"Basically they are guests of the line," says Larry Rapp, manager of special services at Royal Viking. "For the most part, except for a few unusual situations where additional fees are paid, most of our guest lecturers and clergy are given passage and other ship amenities in exchange for lectures or services."

Ship accommodations for one adult on the Star's recent 55-day South American cruise ranged from $6,328 to $14,728.

Royal Viking's guest list has included author Irving Stone, columnist Sylvia Porter and astronaut Gordon Cooper. Columnist William Buckley joined the line's current world cruise. One cruise line extends its invitation to doctors and counselors for children. The doctors, who are required to be on call every other day, sign a contract and are paid a token $1 fee in order to be covered by the ship's malpractice insurance. The youth counselors provide baby-sitting service on ships that take aboard children.

Listed as passengers, but considered as staff, the special personnel dine and mingle with passengers. Their main task is to help while away the hours at sea. "If we didn't have these people, I would have to substitute films," says Derek Mann, cruise director for the Star. "I would much rather have human beings than films."

Kathleen Armour, dressed in a bright yellow sweater and yellow slacks, greeted a visitor at the door of her cabin and introduced her husband of 46 years. The lean and trim yoga-practicing and jogging Richard Armour looked up and waved. Then he went back to autographing a couple of his books for a waiting passenger.

At 72, Armour is the author of more than 55 books and contributor of more than 6,000 pieces of light verse and prose to U.S. magazines. Armed with his worn typewriter, briefcase, two leather-bound maunscripts and two cartons full of his books, Armour set up a temporary office in his cabin during the 55-day trek around South America.

"I do the cruise mostly to please my wife," explained Armour, who usually stays aboard ship when it is in port. Between his 13 lectures, which he gave about every fourth day, Armour managed to crank out 100 verses and five articles. "Financially," he says, "I could be doing more at home. But I consider this book promotion.

"Lectures on a ship are different. Usually I go to one group -- librarians, doctors or bankers -- and give one lecture. Here we have disparate groups of people. The difficulty is to try to amuse, edify people. We're supposed to enlighten."

As a result, Armour's lecture topics run the gamut from the history of American humor to his experiences in Germany during the first year of Hitler's rule. Attendance at his 45-minute sessions usually runs from 200 to 400.

At his closing lecture aboard the Star, Armour arrived dressed in a blazer, gray slacks, a light blue shirt and striped tie -- apropos for the Harvard man he is.

He stepped up to the podium and pulled out a letter he received from the Harvard Alumni Association five years ago. The letter, addressed to the executor of Richard Armour's estate, expressed sorrow over the passing of an alumnus. "I sent them back a note and said be patient. Death is eventual, only the time is uncertain. I never got an answer back."

"Only someone named Eve could go as Eve," said Rabbi Benjamin Wechsberg of his wife's masquerade as the Biblical Eve (complete with flesh-colored leotard, a fig leaf, serpent and apple) at a ship party. "I didn't even go and I asked her not to. But, you know, with woman's lib and all.

"I'm rather conservative. I may not be a social lion, but that's not what I am here for," explains the retired 67-year-old rabbi who lives in Rancho Palos Verdes, Calif., about an hour's drive from downtown Los Angeles. "Long cruises usually have clergy. On the shorter cruises, clergy are aboard when the high holy holidays, Passover, Christmas or Easter coincide with the trip."

The robbi, who took an early retirement in 1971 after suffering a stroke, says that any of the lines that deal in a port city like New York, San Francisco or Los Angeles contact the Board of Rabbis' executive secretary when they want a rabbi. "After you have been established with a line, they will contact you.

"It's a barter arrangement. They give me room and board and I give them whatever services are required. We pay our own on anything not strictly related to the use of the bed or table where we eat. Personally, I could live without seeing Buenos Aires, but my wife enjoys it."

The rabbi holds Sabbath services, special services upon request and counseling sessions. "It isn't as easy as it sounds: I don't come with 10 sermons laid out. If you want to be effective, you can't. To me, personally and professionally, it is a challenge to accomplish in 10 weeks what it takes 10 years to do in a pulpit.

"The only thing I resent is when one of the staff calls this the 'love boat.' It is so juvenile, so sophomoric." The rabbi's informal tally of passengers indicated that the average age was 76. "I said we should call the ship "the Spirit of 76."

The queen of hearts of the ship's bridge players stood in the blood-red Starlight Theater. Perched on stage, Ruth Zillgitt of Palm Springs, Calif., was scribbling on the blackboard. "It looks like algebra, doesn't it," she said, laughing, as she checked out the bridge play she was about to explain.

One might say she was decked out for her bridge lesson -- held daily when the ship was at sea. The theater lights bounced off her black blouse with a card print design and the red heart, black spade, white club and red diamond strung around her neck. Her tiny king-of-hearts earrings swung delicately from her ears.

"Bridge players are bridge players. They would rather play bridge than eat," says Zillgitt.

Zillgitt, the mother of two grown sons, describes herself as "footloose and fancyfree, eager to see the world." For the past five years she has managed to do so by coordinating bridge activities aboard the various ships of the Royal Viking Line.