EVER SINCE Magellan's ship circumnavigated the globe in 1519-22, people have been duplicating the feat by one means or another. Jets have cut the time from years to hours, but even now an around-the-world trip is something of an unusual adventure.

A few rare travelers, with perhaps something to prove, have successfully braved the seas in solo voyages from east to west (or vice versa), but most of us would welcome some means a little less intrepid. For which, in these days, we must pay a fairly hefty sum.

Among the variety of ways to circle the globe:

* It isn't the cheapest, but it may be the most romantic. The people who run the Windjammer Barefoot Cruises in the Caribbean have scheduled a nine-month, 46-port around-the-world cruise on the M/S Yankee Trader, a two-masted motor and sailing yacht carrying 84 passengers and a crew of 26.

It sets sail from Freeport in the Bahamas on May 16 and heads west through the Panama Canal to fabled ports of the Pacific: Easter Island, Pitcairn Island, Tahiti, Moorea, Bora Bora, Pago Pago. And that's only the first three months. On to the Solomons, New Guinea, Bali and Singapore. Then Sri Lanka; the Seychelles; Cape Town, South Africa; and Recife, Brazil, before docking again in Freeport on Jan. 22, 1984.

On a trip like this, says a spokeswoman, the passengers have a voice in how long the ship will remain in any port, though at least half of the travel time is spent ashore. The price is the big catch: $15,000 for a regular cabin or $17,000 for a deck cabin. But of course, she adds, that includes "plenty of grog."

For information: (800) 327-2600.

* If luxury is what you have in mind, such cruise ships as Cunard's Queen Elizabeth II and Holland America's Rotterdam regularly schedule globe-encircling voyages. You can stick with the ship the whole distance (as most passengers do), or sail only on one segment and fly the rest of the way around.

QE2's next trip is tentatively set for Jan. 16, 1984 from New York City, returning 87 days later. Among the ports-of-call: Venezuela, Panama, Hawaii, the Philippines, Japan, Hong Kong, India, South Africa, the Suez Canal, Israel, Greece, Italy and England. Prices have not yet been set, but the rates for this year's 89-day Pacific Cruise (now under way) began at $15,440 for an inside cabin and topped at $250,000 for a four-person suite.

Holland America is celebrating the silver anniversary of its world cruise with the Rotterdam's 82-day voyage that departed New York City at 10 p.m. on Jan. 8. Each year, the itinerary changes, but this year the Rotterdam is visiting Colombia, Panama, Acapulco, Los Angeles, Hawaii, Hong Kong, Shanghai, Sri Lanka, Bombay, the Suez Canal, Egypt, Israel, Greece, Cannes and Lisbon. An inside cabin begins at $15,585 and a cabin deluxe is $35,275 per person. To celebrate the anniversary, Holland America has planned a number of special events en route. In Hong Kong, the lucky passenger winning the raffle gets a new Rolls Royce. How's that for luxury?

For information on cruises: Contact a travel agent.

* The Adventure Center of Oakland, Calif., will get you started on overland treks (four-wheel drive trucks) from London to Nepal, with monthly departures April to October. From Nepal, you can catch a flight onward to complete the circle.

The overland leg takes about 12 1/2 weeks and may be a little rugged, since nights are spent camping in two-person tents. The average group size is about 20. The daily itinerary is fairly flexible, depending on the group's interests, though the guide has final say. In past years, the route passed through Iran and Afghanistan, but nowadays the travelers fly over Iran and skirt Afghanistan through Pakistan to the south. The fee is $2,070, including transportation, food and tent. Airfare beyond is extra.

For information: (800) 227-8747.

* The same group, Adventure Center, will put you aboard a train in London and send you across Europe and the Soviet Union (via the Trans-Siberian Express) to the Sea of Japan, where a Russian cruise ship completes the journey to Japan. From Tokyo, the flight back home can be via Hawaii. The London-to-Tokyo itinerary is 21 days, with overnight stops and excursions in several cities. The price is $1,660 plus airfare. Travel agents offer other trans-Siberian rail excursions.

For information: (800) 227-8747 or a travel agent.

* Another transcontinental rail trip is The Central Kingdom Express, an unusual 45-day, 9,331-mile ride across Europe from London to Paris, Berlin, Warsaw, Moscow, Mongolia, Peking, Canton and Hong Kong (or vice versa), with three departures monthly April to October. A tour leader escorts the group (maximum number is 23) on a variety of trains along the route, with "best available" accommodations in sleepers and hotels during stopovers. The price is $6,100, which includes airfare to London and the return trans-Pacific flight from Hong Kong to the United States (plus all meals London to Hong Kong). A shorter version is the 26-day Red Arrow Express at $3,900.

For information: Express International Inc., P.O. Box A, Main Street, Saltillo, Pa. 17253 (800) 458-3606.

* Two U.S. airlines, Pan American (833-1000) and Trans World Airways (737-7400), advertise around-the-world flights at $1,999, based on their routes and participating foreign lines. Pan American makes the most-complete circle, with a short break between India and Singapore served by Thai International. Air Singapore carries TWA passengers beyond Athens through Asia and back to the West Coast.

Both U.S. airlines place certain restrictions on this fare. The ticket must be purchased three weeks in advance, and there can be no backtracking on the trip. But travelers can make an unlimited number of stops, and only the first leg must be booked, with the rest of the itinerary left open. Pan Am's ticket is good for 180 days and TWA's for a year. Pick up route maps and compare flights across Europe, the Middle East and Asia.

For $2,599, TWA and Quantas, the Australian airline (800-227-4500), offer an around-the-world ticket that includes the continent of Australia. Heading west this time from Los Angeles or San Francisco on Quantas, the traveler can stop at Honolulu and Tahiti en route to Sydney. Beyond, the itinerary can vary, but one route continues from Sydney to Manila, Hong Kong, Bangkok, Kuala Lumpur and Athens. From there, return to the United States on TWA's routes through Europe.

With enough money, it should be apparent, you can arrange practically any around-the-world itinerary that suits your fancy. With enough time (and a certain amount of spunk), you can still plot out an adventurous journey but at considerably less cost by utilizing local buses, trains, ferries and freighters whenever possible.