If one word can describe the plans the Australians have made for celebrating their bicentennial this year, it has to be "fun." The Aussies have put together a program that, this being a historical occasion, takes a look at the nation's past. But the heart of the festivities is just plain good times, and some of it wild and woolly -- not unexpected from a country that still lives something of a frontier life.

The island nation's 16 million residents (in a land about the size of the United States) have "a great sense of fun," says embassy press spokesman Ian Dawes, "and they'll send themselves up for this."

Brisbane's six-month world's fair -- World Expo 88 -- surely will be the biggest event of the year (for visitors as well as the Australians themselves) although for sheer spectacle it may be outclassed by the majestic parade of tall ships in Sydney's beautiful harbor on Jan. 26. "All of Sydney, whether they've got dinghies or yachts, will launch themselves" into the harbor to take part, says Dawes. Hydrofoils and other craft "will be darting in and out" of the procession, and "ferryboats will be hooting and tooting."

Australians have a reputation -- embellished by the popular movie "Crocodile Dundee" -- as a hardy, outdoors lot. So it should come as no surprise that a large part of the festivities includes rough and tumble sports competitions. Among the muscle-stretching events: a 10,500-mile relay race around the country for 16,000 runners; a 4,000-mile hot-air balloon race across the continent; a world boomerang championship; and a race among 130 yachts to circumnavigate the Australian continent.

The focus on fun rather than history may come from the fact that the nation's beginnings were inauspicious. When the United States celebrated its bicentennial in 1976, it could look back 200 years to a dramatic war for independence, to noble words and inspiring leaders. When Australians recall their origins -- which they have sometimes been reluctant to do -- it is to a fleet of 11 British ships carrying 736 convicts, many of them in chains, into enforced exile in an unknown land on the fringe of the world.

This was the famous First Fleet, which took eight months to make the harrowing voyage from London, landing at what is now Sydney on Jan. 26, 1788 -- the date that is being celebrated with a year-long calendar of activities.

The fact that they were convicts, however, does not mean that Australia's founding citizens -- men, women and even some youngsters -- were all hardened criminals. On the initial voyage, as author Robert Hughes points out in "The Fatal Shore," his excellent new account of the nation's founding, many were transported for only minor offenses -- the theft, for example, of small amounts of food to keep themselves and their families from starving.

So what is it actually that the Australians will be celebrating? "The fact," according to bicentennial promotional literature, "that they have traveled during 200 years from cruel and humble beginnings as a penal colony in Sydney in 1788 to a modern nation." The theme for the anniversary is "Living Together," chosen, says the Australian Bicentennial Authority, "because it was considered an important aspiration in a country that has drawn its people from some 120 countries."

Though good fun seems uppermost in the roster of commemorative activities, the past certainly will not be overlooked this year. Tributes to the early pioneers -- among them, political prisoners from Ireland and free settlers -- are planned. And in this era of cultural awareness, efforts are being made, says the authority, to foster "a greater appreciation of Aboriginal history" and to recognize "Aboriginal contributions to today's Australia." The Aborigines, who have lived in Australia for 40,000 years, "suffered severely from the arrival and spread of European settlement."

One of the big history-related projects is a huge traveling roadshow, made up of as many as 40 trailer trucks filled with historical and cultural exhibits. Called the Bicentennial Exhibition, the parade of trucks will tour the country this year, setting up tents at small towns and large cities like a traveling circus. At each stop, says Dawes, the local history buffs will be given exhibition areas to stage their own hometown shows. "Some pretty wild and wonderful stuff should come out of this."

The reenactment of the voyage of the First Fleet is part history and part adventure. Eight modern-day sailing vessels departed Portsmouth, England, on May 13 last year, exactly 200 years after the First Fleet left the same port. The ships already have reached Australia and are scheduled to arrive in Sydney on Jan. 26 to join the Tall Ships parade.

A third aspect of the year's celebration is the arts. Major arts festivals -- music, dance, literature, painting, sculpture, folk art, film -- are planned for the cities of Sydney, Adelaide and Perth. They will feature both noted Australian artists -- opera superstar Joan Sutherland among them -- and visiting performers such as Washington conductor Mstislav Rostropovich, who will give a cello recital in Adelaide on March 22.

About 375,000 Americans are expected to visit Australia in 1988, according to John King of Tourism Australia in Los Angeles. A great many of them will be headed for the world's fair in Brisbane from April 30 through Oct. 30. Because of the long run, accommodations are expected to be available much of the time. Several U.S.-based tour companies are offering travel packages that include visits to the fair. In Sydney, however, lodging space at this late date for the Jan. 26 tall ships parade is extremely tight.

This country's official birthday gift to Australia is $5 million for a wing in the dramatic new National Maritime Museum in Sydney -- to be opened later this year. Sited near Pyrmont Bridge in Darling Harbour, a freshly renovated dockyards area, the steel-and-glass structure rises in places to 10 stories, giving it a commanding view of the city.

As a souvenir of a visit to Australia in its 200th birthday year, travelers should take warmly to Expo Oz, the official World Expo 88 mascot. He's an energetic little platypus, a distinctive Australian river animal with a duckbill, who will be dressed in what foreigners consider Australia's national costume -- the safari suit and the large Aussie hat with an upturned brim.

If you are planning a trip to Australia this year, here's a closer look at the major bicentennial events:

World Expo 88, Brisbane. With concern for the fair-goer's comfort, officials chose to hold World Expo -- the country's first world's fair in 100 years -- during Brisbane's mild winter season, when average temperatures range between 54 and 77 degrees and days mostly are full of sun.

The 98-acre fair site is located on the south bank of the Brisbane River, a short walk from the city heart and adjacent to the state of Queensland's new cultural center. Massive "sun sails," seven of them in soft colors designed to give the fair a distinctive appearance, will be suspended high above the fair site.

More than 35 nations, including the United States, will present exhibits on the definitely fun-loving theme of "Leisure in the Age of Technology." And a look at the fair's schedule of events reinforces the conclusion that this bicentennial is more interested in the lighter aspects of life today.

A 10,000-seat open theater fronting on the Brisbane River will be the site for big-name entertainment featuring Australian and visiting performers. The river itself will serve as the stage for daily water shows, aquacade extravaganzas with massed synchronized swimmers and high-diving stunts. Nearby will be a European-style piazza for theater-in-the-round revues and international circus acts. The Queensland cultural center will present a season of ballet, theater and opera.

The fun goes on in what fair officials describe as a "space-age, high-tech amusement park," 12 acres where, it is promised, visitors can be tempted by "the most unusual and challenging rides in the world," some of them created just for the Expo 88. Each night will conclude with a 15-minute fireworks spectacular.

The fair will be open daily, 12 hours a day, from April 30 through Oct. 30. Daily admission is about $17.50 (U.S.).

Australia Day, Sydney. Two colorful events this year mark Jan. 26, Australia's version of the Fourth of July.

One is the reenactment of the arrival of the First Fleet in Sydney. Eight ships have retraced the 15,000-mile route of the original 11 ships from Portsmouth to Tenerife in the Canary Islands; Rio de Janeiro; Cape Town, South Africa, and Sydney. The other is the tall ships parade. As many as 60 ships are expected, including the U.S. Coast Guard's training ship, the Eagle.

Before the parade, the ships will take part in a 1,000-nautical-mile race that gets underway in Tasmania on Jan. 14 and concludes in Sydney on Jan. 19. The parade itself is scheduled for 2:30 p.m. in Sydney's harbor.

As Americans did at their own bicentennial, the Aussies are likely to spend much of the day and the evening in impromptu street parties, picnics and barbies -- their word for barbecue. The day ends with a massive fireworks display.

Adelaide Festival of the Arts. Though Adelaide has presented an arts festival on alternate years since 1960, this year's, to quote officials, should be a "blockbuster."

The festival, which runs from March 4 to 26, gets going with a massive opening night extravaganza featuring a giant stage sculpture outdoors in the city's Elder Park. As a brochure describes it, there will be "amazing lighting, sound and pyrotechnic effects, combined with artists, performers and musicians from Australia and around the world."

The program turns more traditional on March 6 when Dame Judith Sutherland, a native of Sydney, makes her debut at the Adelaide Festival in an evening of operatic excerpts and on March 7, 9 and 10 when Sir Georg Solti and Michael Tilson Thomas alternate conducting the Chicago Symphony Orchestra on its first visit to Australia.

Among the shows that might intrigue an American visitor is a performance by the Water Puppets of Vietnam. The puppeteers stand waist deep in water, subtly manipulating the puppets from beneath the surface. According to a brochure, "the water explodes with jumping fish, fighting knights, colliding buffaloes, foxes chasing ducks, fire-breathing dragons -- the folklore of Vietnam performed to the accompaniment of exotic musical instruments and fireworks." Performances March 15-20 and 22-26.

And, of course, there will be many opportunities to watch Australian performing arts companies, many of them quite innovative. Australia's four state ballet companies and the Tasmanian Symphony Orchestra will combine in a new ballet called "Vast" for 69 dancers. "Vast" is described as mirroring the diversity of the country's landscape -- "the reefs and coastlines, the deserts and rain forests and, of course, the urban situation in which most Australians live." Performances March 17, 18 and 19.

New Parliament House Opening, Canberra. On May 9, Queen Elizabeth will open Australia's new Parliament House in the capital city of Canberra. A decidedly modern structure built to appear as if it is emerging from a hillside, it replaces an overcrowded provisional Parliament House that has served the House of Representatives and Senate since 1927.

Constructed primarily of Australian materials, it sits on Canberra's Capital Hill. The gently curved walls blend with the circular form of the hall. Of interest to sightseers, the design is said to evoke "the story of Australia in architecture, interior design, light and color modulation."

A massive and very prominent flag mast rises more than 240 feet above the roof of the new building, providing what its planners see as "a strong and memorable emblem of the center of government in Australia."

The relay race for 16,000 runners gets underway from Canberra on the same day. The route is counterclockwise around the country, passing through each of the state capitals and returning to Canberra on Dec. 13.

Special exhibits. Throughout the bicentennial year, visitors interested in learning more about Australia's history and its visual arts can take advantage of several special exhibits.

Until Jan. 31, the Australian National Gallery in Canberra is holding a retrospective exhibit of about 400 works of painter Fred Williams, regarded as one of the country's finest artists. His painting, according to an exhibit announcement, "expresses the subtlety of color and vastness of the Australian bush in a way perhaps no other artist has achieved." After January, the show will tour Australia's state capitals.

In conjunction with the Adelaide Festival of the Arts, there will be a show of Aboriginal weavers working as they did thousands of years ago. And the country's finest print and poster art also will be displayed in a show called "Right Here Right Now -- Australia 1988."

Among the first exhibits planned for Sydney's new National Maritime Museum are "The Discovery of Australia," from the first human contact to European exploration, and "Immigration" -- those who have arrived by ship, from the early convicts to more recent boat people of Southeast Asia.

The competitions. If you want to watch the Aussies having a good time, show up for one of these events.

The big Trans-Australian Ballooning Challenge lifts off in spectacular color from Perth on March 30 bound eastward across the continent to Sydney, where it is expected to arrive two weeks later on April 15.

Top competitors from around the world will meet May 8-14 for the World Boomerang-Throwing Cup in the frontier-like town of Alice Springs in the desert outback of central Australia.

Australia's longest yacht race, a 7,000-mile circle around the continent, sets sail from Sydney on Aug. 6. The finish, back in Sydney, is expected about 100 days later -- in plenty of time for the bicentennial year's concluding ceremonies on Dec. 31.