With a colonizing fervor suggestive of 17th-century sea powers, the world's cruise lines are steaming to exotic ports and untested waters in an effort to entice the sailing public on board.
While others in the transportation field are watching their diets in an era of continuing austerity, the cruise lines are laying on a smorgasbord of new offers this winter. The reason for all this marketing energy is the planned arrival of 19 new or extended ships and 15,000 new berths between 1982 and 1985.
''What happened,'' an industry spokesman said the other day, ''is that the cruise lines went wild building and expanding after a big flush of success in the mid-1970s, so all of a sudden in the midst of some tough economic times they're faced with filling all those berths.''
The papers are full of ads wooing passengers with such bonuses as free air passage to and from port, free cruises in 1984 for those who sail in '83, and big reductions on vacations unrelated to the cruises themselves. The lines have also been forced to alter their sailing patterns, enter more profitable regions, cut down on the length of cruises, and offer segments of longer cruises. These moves are designed to reach a new wave of customers who don't have the time or money to spend months at sea.
More and more ships are showing up this winter on the Mexican Riviera, steering away from Bermuda, the Bahamas, and the Caribbean, where the lanes had become crowded in recent years. Princess, Carnival, Sitmar, Royal Viking Line, Paquet, and now Holland America are sailing on the Mexican seas.
Most of them head south out of Los Angeles (technically, San Pedro), but Holland America's Nieuw Amsterdam, christened only this summer, hopes to grab its portion of the West Coast market by using San Francisco as home winter port. This third Nieuw Amsterdam, a 1,210-passenger behemoth, was built in the same French shipyard that turned out the legendary SS France and the Ile de France. There is a New York theme from stem to stern: a Stuyvesant Lounge, a Big Apple disco.
Another new entrant on the California-Mexico run is Sitmar's Fairsky (which may sound like a Polish liner but should be read and said Fair Sky).
Royal Viking Line, among the top two or three lines for posh service and accommodations and never short on imagination or marketing strategy, has not only stretched its three ships - the Sea, Sky, and Star - by 93 feet but has steamed into a western Pacific battle with Pearl Cruises. This is an area that had shrunk to almost no service with the burning a few years ago of the Prinsendam. Now Royal Viking is selling out 14-day trips from Hong Kong to Kobe, Japan, with stops in a handful of Chinese ports and is also doing a winter series Down Under between Sydney and Papeete (Tahiti) calling at such inveigling ports as Bora Bora, Apia, and Suva. That's a long way from home for the mostly Scandinavian officers and crew, but perhaps the New Zealand coast will suggest to them the fjords of Norway.
Sun Line Cruises, with its small, smart, Greek-run trio of ships, will reward winter customers with later vacations valued at $1,000 at a number of Marriott resorts. But this Breakaway Bonus program is pure come-on compared with the appeal of two inaugural cruises up the Amazon aboard the flagship Stella Solaris. The Solaris, which wiles away the summer in the Aegean, will nose out of Fort Lauderdale Dec. 16, plow through the Caribbean with several stops, and then sail 1,000 miles up the Amazon finally docking in Manaus. There passengers will be treated to a special performance at the Amazonas Theatre, a remarkable neoclassical opera house built a century ago in the middle of the jungle when Manaus was a rubber boomtown.
If the Amazon isn't river enough, Sun Line will also plumb Venezuela's Orinoco for the seventh year in a row. From the last stop, Ciudad Guayana, passengers will be flown to the jungle resort of Canaima, passing over Angel Falls, the highest waterfall in the world.
Cunard's Queen Elizabeth 2, though an attraction in itself, has had to struggle like the other cruise ships to keep its share of the market. Having installed the Golden Door spa to make it the world's largest floating health club, the QE2 has lately put in a personal computer center and a staff of experts to guide passengers through the uncharted seas of computer technology. Though it stays off the North Atlantic in midwinter, the QE2 will do an around-the-world cruise out of New York in 89 days leaving Jan. 16, selling segments of 2, 3, and 4 weeks, there being fewer and fewer people who can stay out for three months and pay anywhere from $16,085 to $81,120.
Cost is, of course, a major consideration to cruise shoppers. One's per diem outlay can obviously vary - from $175 to $900 a day on the QE2's marathon. But about $299 per person will buy a comfortable stateroom on most ships, at least four or five meals a day, fun and games on board, trips ashore, and whatever bonuses the increasingly competitive lines are willing to offer during the long and, for some, warm winter ahead.