FOUR hundred miles east of Gibraltar, Tania Aebi could only watch as her 26-foot sailboat slid down the face of a wave, turned sideways, and was nearly swamped. ``The boat lurched, flipped on her side, and my world turned upside down,'' Miss Aebi wrote in Cruising World magazine. Tomorrow, Miss Aebi (pronounced Abby), is expected to sail into New York Harbor after completing a 2-year solo sail around the world. Aebi will join an increasing number of people who are lured to follow such sailors as Ferdinand Magellan, the first man to cross the Pacific, and Captain Joshua Slocum, the first solo circumnavigator.
There is a wave of interest in Aebi's trip. Cruising World magazine says it gets 50 phone calls a day from readers inquiring about Aebi's location. Several publishing companies have expressed an interest in a book about the trip. Aebi - only 20 years old - is scheduled for television interviews when she arrives.
``When anybody that young departs on an adventure that dangerous and does it successfully, it is an example to us all,'' says Peter Neill, president of the South Street Seaport Museum in New York.
Although exact numbers are not available, circumnavigation is a feat more sailors are undertaking.
Ginny Osterhalt, editor of the South Seas Cruising Association in Fort Lauderdale, Fla., estimates that 3,500 people are sailing around the globe. Only a few years ago, an informal census in Tahiti, a cruising haven, found 400 boats a year stopped at the island.
Many of those who start will not finish, says Hal Roth, who has sailed around the world twice. ``It is an arduous business and many people just do not have the determination or spirit for it,'' Mr. Roth says.
Almost all of the modern-day Magellans follow the trade winds west. This takes East Coast sailors to the Caribbean and through the Panama Canal. From there, many start meandering across the Pacific, stopping at islands such as the Marquesas, Tuamotu, Tonga, Fiji, and the French Polynesians. West Coast voyagers can head straight for the South Pacific.
After months or even years of visiting such islands, voyagers usually head around the top of Australia and across the Indian Ocean to Durban, South Africa. The final leg of the trip takes the global sailors around the Cape of Good Hope and into the South Atlantic. Trade winds push the sailboats toward the Caribbean.
Aebi took an alternate route, beating 1,000 miles up the Red Sea before entering the Suez Canal. She then sailed west across the Mediterranean before leaving Gibraltar for New York.
Although Aebi took 2 years to complete her circumnavigation, many sailors take a lot longer. Jak Miner, a retired public relations executive, left last weekend for a four-year trip which he expects to include stops in such out of the way areas as Pitcairn Island in the Pacific; Komodo, an Indonesian island; and the biblical areas on the coast of Turkey. ``If it takes longer, it takes longer,'' says Mr. Miner, who is traveling with his wife and two children. ``We are looking for similarities between the people of the world.''
Long-distance cruisers often leave careers in midstream. This was the case with the Mimi and Dan Dyer, who left Detroit in 1973 for a six-year circumnavigation. Mr. Dyer owned his own manufacturing company; Mrs. Dyer was an editor of a magazine. ``We felt rather than wait until the circumstances are perfect, which is seldom the case, we would take our money, sell our house, and run.'' Roth says the odds are slim a long-distance cruiser will return to a desk job. Many will instead find work in the marine industry.
Initially, the allure of visiting picture-post card harbors keeps cruisers on the move. But, as the Dyers found, ``What ended up meaning the most was the people,'' Mrs. Dyer says. They made deep friendships with other cruisers and islanders. But, more important, she and her husband became closer. ``It was six years of what we all cry about wanting - quality time,'' she says.
After a five-year, 35,000-mile sail, Betsy Holman, executive editor of Cruising World magazine, says she gained ``a better sense of what it's like to be an American. You really don't know until you have lived outside the country.''
The cultural experiences are sometimes tempered by the sea. The Dyers got caught in a ``buster'' - a strong cold front that roars up from Antarctica along the South African coastline. Mrs. Dyer remembers the sky turned black and the wind rattled through the rigging as if someone had grabbed the mast and shaken it. ``The seas were so steep we didn't see a tanker until it was only a quarter of a mile away from us,'' she recalls.
Author Deanna Sclar joined a Colombian family that was refitting a schooner in Panama for a circumnavigation. Between the Galapagos and Marquesas islands the boat lost its mast. They drifted for 6 weeks without a radio before they were rescued.
Most of the time the cruisers follow weather patterns that make circumnavigation easier and avoid cyclone and hurricane seasons.
Another reason sailors are making smoother passages is because of an improvement in navigation technology. Long-distance navigators can still use sextants to measure their position relative to the sun and the stars. Now, many cruising boats also carry SatNav equipment, which determines a vessel's position every 90 minutes from a signal beamed down by an orbiting satellite.
This is not the way it used to be. In 1898, Captain Slocum rebuilt an old oyster smack and took off around the world by himself, a trip the experts said could not be done alone. He left without a chronometer because he did not want to spend $15 to get one fixed and determined his longitude by determining his position relative to the moon. His book, ``Sailing Alone Around the World,'' became a turn-of-the-century best seller.
Slocum's voyage still inspires sailors, says Don Holm, secretary of the Joshua Slocum Society in Port Townsend, Wash. ``Here's a guy who does something on his own and succeeds at it. It seems to strike something inside people,'' Holm says.
The great rush to sail around the world began in the 1960s with the widespread use of fiber glass, which required less maintenance than wooden boats. Now, Holm says, some sailors have made the trip around the globe three or four times. ``It's become a milk run,'' says Holm, who is also the author of a book, ``The Circumnavigators.''
Boat shoes have become so common that sailors have worn out their welcome at some islands in the Pacific and Indian Oceans. ``There is a feeling the yachties are sponging off the local people,'' Holm says. Some islands have strict laws governing transient yachtsmen.
The cost of sailing around the world depends on how often one eats at expensive restaurants or needs expensive repairs. Mrs. Holman estimates that living expenses run $8,000 to 10,000 a year. Some cruisers hope to cash in on their trips by writing books when they return. Miner is planning to make a film of his trip, hoping to sell it to a cable-television packager.
Eric Swenson, executive editor of the W.W. Norton publishing company, says most books don't sell more than 4,000 copies. ``It's not an automatic audience,'' he says. ``They need to have something terrible happen to them.'' For example, a sailor who spent 76 days at sea on a life raft found an instant audience.
Sailors also have trouble adjusting after a long cruise. Following an eight-year circumnavigation, Ray and Shirley Triplett complained, ``We cannot seem to `fit in' anymore.'' Mrs. Dyer estimates it took her three years to become a landlubber again. Many cruisers agree with Slocum, who wrote, ``The days passed happily with me wherever my ship sailed.''