It may almost be time to bid goodbye to the only authentic steamboat carrying passengers overnight on American waters. Fire safety laws have threatened to halt this wooden wedding cake of a vessel dating from 1926, but she's not going down without a fight. Thousands of former passengers and steamboat fans have rallied to the cause, trying to keep the Delta Queen afloat. In the meantime, the National Historic Landmark is still steaming along the Mississippi, Cumberland and Ohio rivers with a full schedule of cruises, greeted at every levee by its loving friends.

For more information: Majestic America Line

No matter how luxurious, most yachts don't provide cabins that can be described as spacious. Sea Cloud does. Book the 500-square-foot owner's suite, a creamy white confection of satin, marble and gilt, complete with fireplace, to experience the oceangoing life of the heiress who occupied it while traveling the world in the 1930s. Nine other restored cabins exist from those days—and they're not too shabby either. Some accommodations were added later, when the yacht was converted into a cruise ship, sailing the Caribbean in the winter and the Mediterranean in the summer. A one-week September trip from Naples to Nice costs approximately $4,200 to $8,600 per person.

For more information: Sea Cloud

The Royal Yacht Britannia was launched in 1953, serving the British Royal family for the next 50 years. In 1995 Queen Elizabeth turned it over to a non-profit foundation that maintains Britannia in the style for which it became famous, while opening it almost daily for tours and hosting corporate events. These include banquets in the State Drawing Room, and will be followed by dancing on the Royal Deck, which has been restored and will open in late 2008.

For more information: Royal Yacht Britannia

One of only three surviving J-class boats, Endeavor was found languishing on an abandoned seaplane base on the English coast in the early 1980s. She was restored in a multi-million dollar effort and re-launched, only later to fall into the hands of Dennis Kozlowski, the disgraced former head of Tyco Industries. In 2006, while behind bars, he sold his trophy sloop for $15 million and—as of this writing—it is mostly being raced in Japan by its new owner. Endeavour "is out of formalized charter" says a top yacht broker," but these situations are fluid.

For more information: Camper & Nicholsons

Aristotle Onassis's 325-foot yacht began life in 1943 as a Canadian convoy escort and no matter how high a gloss it gained in later years, the ship's plainspoken lines speak of its origins. Onassis bought it in 1954 and sailed it as the magnificent Christina O, hosting a complete roster of mid-century celebrities, including the Kennedys (and later honeymooning with Jacqueline), Winston Churchill, King Farouk and Frank Sinatra. Now some 36 guests can revisit those days by chartering Ari's ship for a week-long Mediterranean cruise.

For more information: Camper & Nicholsons

This 104-foot wooden motor yacht dates from 1925 and by 1931 became a favorite of presidents, starting with Herbert Hoover. Franklin Roosevelt fished from its rear deck, and during the Cuban Missile Crisis, John Kennedy held meetings in the main salon. Later, Richard Nixon became convinced Sequoia was bugged and insisted an electronic shield be built around it. All this history is accessible to private citizens at a cost of $12,500 for a chartered event lasting up to four hours.

For more information: Sequoia

"Keep old boats alive" is the cry of Seascope Yacht Charters. A perfect example is their graceful, 12-meter yacht, dating from 1938, with its polished brass fittings and original 91-foot spruce mast. Bought in 1958 by the Greek shipping magnate Stavros Niarchos, she participated in the America's Cup, but many owners later, neglected and abandoned, sank to the bottom of Lake Michigan. Seascope's late owner Bob Tiedemann became Northern Light's savior, raising her from the deep, rebuilding and re-launching this Newport beauty, and allowing new generations to experience yacht racing in the grand tradition. For more information: Seascope

Cinderella afloat, the sturdy little car ferry commissioned in 1965 spent more than 20 years carrying passengers and freight through Scotland's remote western islands as the MV Columbia. In 1989, new owners transformed the workaday vessel into a top-ranked cruise ship holding 49 passengers, with appointments grand enough to have persuaded Britain's royal family to take its summer holiday aboard her two years ago. Commoners can pick from a variety of tempting trips, including "A Hebridean Autumn," a new five-day cruise that starts at starting at $4,300 per person for a double cabin.

For more information: Hebridean Princess

Launched in England in 1920, this is a vessel that commands superlatives: the largest gaff cutter in the world, the largest wooden boom, and the best preserved interior of the great classic yachts, with corridors of mahogany paneling, original light fixtures and furnishings. "Lulworth is among the top 10 most important British yachts of the inter-war period," says one maritime historian, and for $115,000 per week, she's yours.

For more information: Fraser Yachts

Built in 1917 for an Egyptian sultan, the three-deck sternwheeler still cruises the Nile, powered by its original steam engine. Its 15 air-conditioned cabins promise its 30 passengers the best of the modern world set among the ancient splendor of an eight-day round trip tour from Luxor. London-based Voyages Jules Verne represents the ship.

For more information: Voyages Jules Verne