The typical luxury liner goes precisely where you expect it to: It sails the high seas, bound -- as the ads ballyhoo -- for exotic ports in foreign lands. In recent years, however, a most-atypical group of cruise ships has been doing exactly the opposite.

These unusual ships make up the growing fleet of smaller passenger liners -- some quite luxurious, others a bit more spartan -- that ply North America's scenic coasts, bays, waterways and rivers. They turn inland for calm passage and familiar ports from the country's seafaring past.

The junior-sized cruise ships promise relaxation rather than nonstop recreation and entertainment; the intimacy of passenger lists numbering usually under 200 rather than in the high hundreds and more; and informality in place of fancy, dress-up galas. You will find a dining room, lounges, lecture sessions on American history and perhaps a well-stocked library, but never (well, almost never) a swimming pool or casino.

Compared to oceangoing liners, says Lynn Ramsey, a spokeswoman for American Cruise Lines, which operates three of the smaller ships, they are like "a country inn to a Club Med resort. You're left to your own devices to entertain yourself."

This year, American is reporting "heavier-than-normal" advance bookings for its spring and summer schedules. The line's president, Charles Robertson, attributes it to two developments: the declining value of the U.S. dollar abroad and traveler worries about personal security on foreign shores.

"Many of these travelers who might otherwise be cruising the Mediterranean next season," he says, "will instead be rediscovering America in the safety of our own waters."

Robertson anticipates a continuing demand for cruising within the United States, and his firm is expanding. It expects to put two new ships into service -- one at the end of this year and another in 1987.

Among the varied ports of call for the inland fleet are nearby Annapolis, St. Michaels and Yorktown on the Chesapeake Bay; Charleston and Savannah on the Intracoastal Waterway to the south; Nantucket and Bar Harbor on New England's rugged coast; and the great old river towns along the Mississippi and the Columbia in the West.

The American Canadian Line's 80-passenger Caribbean Prince sails up New York's Hudson River and the Erie Canal to Canada -- an especially lovely route when the fall hillsides are ablaze in color. The 140-passenger Savannah of American Cruise Lines crosses the Florida peninsula by way of Lake Okeechobee and the Caloosahatchee River, a 10-day sightseeing journey through a waterscape brilliant with flamingos.

Travelers also can embark in Fort Lauderdale and sail up the East Coast to Boston, a 28-day "Great American Odyssey" aboard Clipper Cruise Line's 100-passenger Nantucket Clipper. It stops at every major port on the Atlantic, and a lot of smaller ones -- 22 in all.

A modern-day replica of a 19th-century riverboat departs New Orleans for St. Paul, Minn., a 21-day adventure into the realm of Mark Twain that traces almost the entire navigable length of the Mississippi. Or you can take shorter trips, offered both by Delta Queen Steamboat Co. and American Cruise Lines, to Natchez, Vicksburg, Memphis and St. Louis.

At least seven companies operate vessels on one or more of these inland routes, several sailing the southern waterways (or the Caribbean) in the winter and returning north as the weather grows warm. Trips range from a few days to a full month. (Another half dozen or more cruise ships sail the Inside Passage from Seattle and other Pacific ports to Alaska, but they are mostly larger ships.)

The inland fleet includes full-service luxury vessels; comfortable Mississippi paddlewheelers; and one tiny New York canal cruiser, the Emita II of the Mid-Lakes Navigation Co. It's so small that passengers must disembark each night to sleep in a hotel or motel because the Emita has no cabins.

Each ship differs in the facilities it provides, but on some vessels passengers will find cabins as large or larger than those on oceangoing liners -- the Emita being an exception, of course. A big plus is that most cabins have an outside view, and many of them have a big picture window instead of the familiar porthole.

The luxury lines try to foster a feeling that passengers are guests aboard a privately chartered yacht, and the small numbers make it easier for travelers to make friends. Dining frequently is open seating rather than at the assigned tables traditional for full-sized cruise ships.

A week's cruise on most of these vessels is not inexpensive, and -- depending on the ship -- you may pay more than you would for a vacation aboard a Caribbean liner. One reason is the personal attention the small ships attempt to provide; another is the fact that the lines have far fewer berths available to sell. In fact, some summer departures are sold out already.

The smaller ships tend to attract older and more affluent travelers -- though the average age is dropping, says Robertson. They tend to be people who enjoy sailing -- the sea views, the opportunity to explore new ports -- but without the resort-life atmosphere that prevails on some of the large liners.

It may be an obvious point, but it should be noted that on an inland cruise the ships are rarely out of sight of land. There is an amazing lot of interesting countryside to be seen from this country's waterways; and from your cabin window or the deck you can spend a week or more watching it glide by.

And: "When you step off," as Patricia Young of the Delta Queen Steamboat Co. puts it, "you step back into American history."

Among this year's inland waterway itineraries:

*The Chesapeake Bay: It should be no surprise to residents of the Washington area that the Chesapeake's historic fishing and sailing communities are popular ports of call for the inland fleet. At least three cruise lines schedule annual visits of several weeks.

American Cruise Lines' ship, the America, will be sailing the bay weekly during the month of May, departing Baltimore on one Saturday and returning the next. It will stop in St. Michaels, Oxford, Cambridge and Crisfield in Maryland and Portsmouth and Yorktown in Virginia.

In St. Michaels, passengers can tour the excellent Chesapeake Bay Maritime Museum, an 18-acre complex of structures and ships that chronicle the lore of the bay. In Crisfield, the focus is on the bay's tasty crabs. History buffs can walk the battlefield at Yorktown, an attractive colonial village, where Washington and Lafayette brought the British to surrender.

The America, one of the most comfortable of the small liners, carries 87 passengers. All of its cabins have an outside view through picture windows that open. The cost of the bay cruise ranges from $1,190 to $1,470 per person (double occupancy) for standard cabins, with suites available for $1,995 per person.

Other American Cruise Lines itineraries include the Mississippi and Ohio rivers; the Maine coast from Rockland; the Carolina islands; and a Hudson River foliage cruise.

For more information: American Cruise Lines, 1 Marine Park, Haddam, Conn. 06438, (800) 243-6755.

*North to Canada: The inland route from New England to Canada is both scenic and historic -- a 12-day voyage from Warren, R.I., to Quebec and Montreal (or vice versa). Two ships of the American Canadian Line -- the 72-passenger New Shoreham II and the 80-passenger Caribbean Prince -- make the trip throughout the summer.

From Warren, the ships sail through Narragansett Bay and Long Island Sound before entering New York Harbor, where this summer passengers will get a look at the newly refurbished Statue of Liberty. Afterward, the ships turn up the Hudson River, sailing past West Point and the Catskill Mountains to the 350-mile-long Erie Canal between Albany and Buffalo.

Though both vessels are narrow enough to enter the canal, the pilot house on each must be lowered so the ships can slip beneath the many bridges along the way.

The next leg of the trip takes passengers across Lake Ontario, through the Thousand Islands and up the St. Lawrence Seaway to Montreal. After a two-night visit, the ships sail up the Saguenay River, a glacial fjord where whales and seals sometimes can be spotted. The final stop is Quebec, a lovely European-like city of narrow, winding streets.

Passengers then are transported back to Warren by bus across Vermont and New Hampshire.

All but a few of the cabins have outside windows. Aboard the New Shoreham II, the cost ranges from $999 to $1,685 per person (double occupancy). The range on the Caribbean Prince is $1,135 to $1,635.

For more information: American Canadian Line, P.O. Box 368, Warren, R.I. 02885, (800) 556-7450.

*Up the Columbia River: The Columbia River cruise is a seven-day round trip from Portland, Ore., that traces the route of the 19th-century Lewis and Clark exploration party; climbs several locks; passes through Indian country and treats passengers to a jetboat ride up the rapids of the Snake River into Hells Canyon in Idaho.

The ship is the 3-year-old Pacific Northwest Explorer, a comfortable 80-passenger vessel operated by Exploration Cruise Lines that offers all outside cabins. Departures are from mid-May to mid-October. Unlike some inland waterway cruises, this one has proven popular with school-age children.

The trip begins with a cruise through downtown Portland on the Willamette River planned so that dinner is served beneath the twinkle of the city's evening lights. Back on the Columbia, the Explorer first sails west to the mouth of the Columbia and Fort Clatsop, the reconstructed fort built by Meriwether Lewis and William Clark, who were sent west in 1804 by Thomas Jefferson to explore America's Louisiana Purchase and an overland route to the Pacific.

The Explorer returns east past Portland, climbs the locks at Bonneville Dam and heads into the Snake River at Pasco, Wash., where it continues on to Lewiston, Idaho. On-shore excursions include the half-day jetboat ride up Hells Canyon and a visit to the Nez Perce National Historic Park, which is partly located on the Nez Perce Indian Reservation. Lewis and Clark spent a month with the Nez Perces in 1805 on their journey west.

While headed upriver, the Explorer stops mostly at Oregon towns; headed back down from Lewiston, the ports are on the Washington side of the river.

The fare ranges from $1,099 to $1,259 per person (double occupancy) in May and October and $1,589 to $1,829 from June through September.

Exploration Cruise Lines also offers itineraries on the Sacramento River from San Francisco to California's Gold Country; small ship cruises north to Alaska and eight-day Chesapeake Bay cruises, departing from Washington in May, early June and November; and New England cruises from Boston in the summer.

For more information: Exploration Cruise Lines, 1500 Metropolitan Park Building, Seattle, Wash. 98101, (800) 426-0600.

*The New England Coast: Two of the finest-looking ships in the inland fleet are the Clipper Cruise Line's Newport Clipper and Nantucket Clipper, which offer seven-day summer cruises to their namesake cities.

The trip begins at Boston at Quincy Yacht Marina. Passengers board Saturday afternoon for an early Sunday departure for the wind-swept island of Nantucket, a 19th-century whaling village of cobblestone streets and weathered cottages.

Back to the mainland, the next stop is the old whaling and fishing town of New Bedford. Then it is on to elegant Newport, America's yachting capital. Passengers will have time to tour the city's famed old mansions.

The cruise concludes with visits to the island of Martha's Vineyard, where the beaches are tempting, and the town of Plymouth, the landing place of the Pilgrims.

Each of the ships carries 100 passengers. The cabins all have outside views. The cost of the New England cruise ranges from $1,395 to $1,785 per person (double occupancy).

Clipper Cruise Line also offers cruises along the Florida coast; the islands of the Carolinas; and the Chesapeake Bay.

For more information: Clipper Cruise Line, The Windsor Building, 7711 Bonhomme Ave., St. Louis, Mo. 63105, (314) 727-2929.

*The canals of New York: From mid-June to mid-October, the little 50-passenger Emita II makes two- to four-day voyages of four of New York State's canals, but principally segments of the Erie, a historically important canal completed in 1825 that is the subject of romantic tales and boatmen's songs.

At least once a year, the Emita travels the full length of the Erie, west from Albany to Buffalo, a seven-day adventure departing Aug. 30 this year. From Albany, the canal passes between the green hillsides of the Mohawk Valley. Along the full route are many canal towns that grew up around the locks.

Meals are served on the Emita, which has a bar, but passengers are taken each night to a hotel or motel. The cost for the seven-day trip is $660 per person (double occupancy), including meals and lodging. Other trips are $240 for two days; $360 for three days and $444 for four days.

For more information: Mid-Lakes Navigation, P.O. Box 61, Skaneateles, N.Y., (315) 685-5722.

*The St. Lawrence River: The Bahama Cruise Line's Veracruz sails weekly on a seven-day voyage between New York City and Montreal from mid-June to mid-September. That makes it an inland cruise, but in most other aspects the Veracruz differs from the rest of the inland fleet.

It is a large, full-service liner, carrying about 700 passengers, and it has a swimming pool, a casino and a large number of inside rooms.

These exceptions noted, the Veracruz does make an interesting voyage. From New York, it sails up the coast to Newport, R.I.; through the Cape Cod Canal and on to Sydney, Nova Scotia. From there, it enters the St. Lawrence River, takes a side trip up the Saguenay Fjord and then concludes with stops at Quebec and Montreal.

The fare ranges from $875 per person (double occupancy) for an inside cabin in early summer to $1,205 for one of the best cabins during the peak summer period (mid-July to mid-August).

For more information: Bahama Cruise Line, 4600 West Kennedy Blvd., Tampa, Fla. 33609, (800) 237-5361.

*The Mighty Mississippi: And the Ohio River, too. Once more than 11,000 paddlewheelers -- many of them floating palaces -- traveled the Mississippi and Ohio rivers, carrying passengers and cargo from America's heartland to New Orleans, one of the country's most exciting cities.

The Delta Queen Steamboat Co. operates two paddlewheelers throughout the year, the 180-passenger Delta Queen and the 420-passenger Mississippi Queen (temporarily undergoing repairs until April).

The Delta Queen, at age 60, is the oldest, an authentic passenger steamboat that first sailed the Sacramento River in California in 1926. It is not as luxurious as the much newer and larger Mississippi Queen, but it has its own special charms: fine woodworking, polished brass, stained-glass windows, all outside cabins and a more intimate feeling.

And because it is smaller, you get a sense of being closer to the river.

The Mississippi Queen more closely resembles a large liner in its amenities: large cabins, more bars, a gym, sauna and whirlpool hot tub. The atmosphere is more lively. It has some inside cabins.

Both vessels offer three- to 12-day river cruises, either round trip from New Orleans or another city or one way between two ports on the river.

For example, the Delta Queen's seven-night "Heart of Dixie" voyage -- offered several times a year -- departs New Orleans on a round trip with stops at Vicksburg, Natchez and Baton Rouge. The rate ranges from $910 to $2,450 per person (double occupancy).

American Cruise Lines' brand new riverboat New Orleans, carrying 140 passengers, will make the 21-day voyage from New Orleans to St. Paul once only this year, departing May 24. The fare ranges from $3,570 to $4,410 per person (double occupancy), with suites at $5,985.

For more information: Delta Queen Steamboat Co., 30 Robin Street Wharf, New Orleans, La. 70130-9990, (800) 543-7637. American Cruise Lines, One Marine Park, Haddam, Conn. 06438, (800) 243-6755.

*The Atlantic Intracoastal Waterway: Taking advantage of rivers, bays, sounds and canals, the Intracoastal Waterway provides protected passage for small craft for more than 1,000 miles from Florida to the Chesapeake Bay. And with some open-ocean travel, the inland route continues north to Boston.

Several lines offer trips over part of this route, mostly in spring and fall, but Clipper Cruise Line's Nantucket Clipper makes the entire voyage twice a year -- a total of 28 days each way. In the spring, it sails north from Fort Lauderdale to Boston; in the fall, it makes the return trip to Florida.

This year's spring sailing, departing Fort Lauderdale May 10, already is sold out; but space still is open for the fall trip, departing Boston Sept. 20. On the southbound leg, ports include many of the East Coast's most popular cities and resorts: Nantucket, Newport, New York, Philadelphia, Annapolis, Yorktown, Norfolk, Charleston, Hilton Head, Savannah, St. Augustine and Palm Beach.

Between the cities are miles of sand dunes, cypress swamps, forests and farms and countless seaside villages. The fare for the month ranges from $5,180 to $6,740 per person (double occupancy).

American Cruise Lines offers 14-day trips on the waterway between Savannah and Baltimore in April, May, October and November. The fare ranges from $2,380 to $2,940 per person (double occupancy). The line's 10-day Lake Okeechobee cruises, between Savannah and Fort Myers, Fla. take in part of the waterway. They are winter trips, continuing into April. The fare ranges from $1,700 to $2,100 per person (double occupancy).

American Canadian Line's two ships also sail the waterway, north in spring and south in fall, between West Palm Beach, Fla. and Warren, R.I., taking 15 days to make the voyage. The fare ranges from $1,060 to $1,995 per person (double occupancy).

For more information: Contact the appropriate cruise line at addresses and phone numbers listed above.