A chapter in American maritime history will close Tuesday when the last car and passenger-carrying steamboat in North America sails out of Woods Hole harbor.

The retirement of the SS Naushon from the Steamship Authority fleet marks the end of a 170-year era of steam ferry service along the Eastern seaboard.

Soon to be painted in the red, white and black colors of her new owner, the Bay-State Spray and Provincetown Steamship Co., the 229-foot vessel will sail for her new home at Commonwealth Pier in Boston harbor where she will be transformed into a cruise ship restaurant.

The Naushon was scheduled to leave early this week, but the 31-year-old former stalwart of the fleet was pressed into Vineyard service one last time. Her five-month old, $8 million successor, the MV Eagle, was forced into emergency drydock in Newport, R.I., with propeller damage.

“No more heavy lifting for this boat,” said Joseph G. Palotta Jr., chief executive officer of Bay State boat line. “Her days of hard work will be over. From now on it will be just cruising around Boston harbor for three or four hours at a time.”

The departure of the Naushon leaves the Islands of Martha's Vineyard and Nantucket without the services of a steamship for the first time since 1818. The seven remaining ships of the authority fleet are all powered by diesel plants.

“Just years after Robert Fulton made his first steamboat voyage in New York, there were steamboats going to the Islands,” said Robert Cleasby, a president of Friends of Nobska, a steamship preservation society. “It's sad to see it all end.”

To authority passengers on the Naushon was the grand dame of the Great White Fleet, the symbol of another era in Vineyard history.

She was recognized as the most powerful, smoothest sailing vessel in the fleet and was the sentimental favorite among Island travelers.

SSA general manager Barry O. Fuller, who served as captain aboard the Naushon from 1980 to 1984, is glad finally to dispose of what has ling been regarded as the white elephant of the fleet.

“From a personal standpoint I hate to see her go,” Mr. Fuller said. “There is a strong sense of nostalgia attached to her. But from a management perspective, she was no longer economically viable. Of all the authority vessels the Naushon was the truest ship in the fleet. She was a challenge to sail. The other vessels are more like Greyhound buses.”

In December the SSA sold the Naushon for $150,001, far short of its original $1 million asking price, but the new owners agreed to pay the high cost of her mandatory drydocking.

Under terms of the purchase and sales agreement, the Naushon was kept at Woods Hole until the arrival of the MV Nantucket, which underwent a prolonged drydocking and repowering maintenance in Louisiana this winter.

The SSA planned to use her this weekend if the Nantucket did not arrive as planned. Her last official sailing as an SSA vessel was Oct. 29, 1987.

“The name Naushon is very special to me,” senior SSA governor James H. Smith of Falmouth said. “I remember when the fleet consisted of the first Naushon left during World War II for service and didn't come back.

“The present Naushon had problems from design through service through the present time but it's always sad to see an old, dependable friend leave and I was certainly glad I insisted we keep it until now in case we needed her.”

in recent years the authority has come to regard the vessel as a major financial drain. The costs associated with her upkeep and operation have grown more burdensome each year.

Her ravenous thirst for fuel and her propensity for damaging SSA piers during docking make her a financial liability. In addition, the antiquity of her two rare, 2,000-horsepower reciprocating steam engines make repairs difficult and costly and require an expanded crew, Mr. Fuller said.

The Naushon burns 32 gallons a mile compared to the average 6 gallons consumed by her sisters on the fleet. In recent years the authority appropriated between $50,000 and $60,000 a year for pier repair directly attributable to the Naushon, Mr. Fuller said.

Despite the economic drawbacks, Mr. Cleasby has long argued to the authority that maintaining the Naushon makes long-term economic sense.

“The added cost she incurs because she is a steamboat and because she occasionally hits a dock is still cheaper than financing a new boat,” Mr. Cleasby said. “If she were worn out and her hull was gone, then certainly she should go, but she's got 15 or 20 good years left in her.”

The $2.4 million vessel was built by the J.H. Mathis Company in Camden, N.J., and launched in 1956 and christened the SS Nantucket before her name was changed. The Naushon's debut in Vineyard waters set the pace for the love-hate relationship that would develop in subsequent decades.

On the occasion of the vessel's maiden voyage to the Vineyard, Gazette reporter Joseph Chase Allen wrote: “Impressions of the Nantucket as briefly seen...are first an impressive lack of beauty. She is short for her height and her beam, when head on, appears narrow.

“There is ample room everywhere except in the corridors and stairways, which resemble the curious windings of a rabbit hole and are too narrow for two people to move abreast.”

In 1980 the boat line put out bids to restructure the vessel and fit her with new diesel engines, but when bids came in between $6 and $12 million the project was abandoned.