Fewer passengers rode the Steamship Authority ferries last year, continuing a trend under way since the turn of the millennium.

The boat line, which provides the only year-round passenger and vehicle service to the Islands, carried 2,609,835 passengers last year, off 63,324 or 2.4 per cent from 2004.

Passenger traffic on the Vineyard route fell 3.1 percent.

"This is the third year we've been down three per cent," Vineyard SSA governor Marc Hanover said yesterday. "There are more people living here, fewer people visiting."

The boat line also reports that its ferries carried 1.4 per cent fewer automobiles last year, but 11.7 per cent more trucks, setting a record. Overall vehicle traffic ran 2.6 per cent ahead of last year.

SSA general manager Wayne Lamson said Wednesday that ridership is off 13 per cent, or almost 400,000 passengers, from what he defines as the boat line's high-water mark, when it carried just over 3 million passengers in 2001.

The SSA carried slightly more passengers in 2002, but that included ridership from the ferry Schamonchi, which the boat line operated between New Bedford and Martha's Vineyard in 2002 and 2003.

Mr. Lamson attributed the continuing decline in boat line passengers to factors such as the sluggish economy and higher gasoline prices, which he said gives families less discretionary income to take trips to the Vineyard or Nantucket.

To reverse the trend, he said the SSA plans to pursue group tour business more aggressively, and to better market private bus service that links Boston and Logan Airport with the boat line's Vineyard ferries out of Woods Hole.

"We're working it," Mr. Lamson said.

Mr. Lamson said he met Tuesday with representatives of Peter Pan/Bonanza to discuss how to promote the ferry-bus link to and from the Vineyard.

Mr. Hanover said: "We need to encourage more passenger traffic." He said that is why he pushed to have the boat line conduct a study this year of the fees charged to licensed private carriers that compete with the boat line, such as Hyannis Harbor Tours, commonly known as Hy-Line.

While the carriers are in business to make a profit, Mr. Hanover said, the boat line mandate is to provide a service.

Traffic was up for passengers, automobiles and trucks on the Hyannis-Nantucket route.

"I think part of that is the Steamship Authority is the least expensive method of travel between Nantucket and the real world, less expensive than the Hy-Line, less expensive than airplanes," Nantucket SSA governor Flint Ranney said. "Perhaps we've reached the end of a down trend."

"I think the service attitude of Steamship employees has improved dramatically and that people are happier with the Steamship's operation," Mr. Ranney said.

The SSA released the annual traffic numbers several days before its next meeting, scheduled for 9:30 a.m. Tuesday at the MBL Candle House on Water street in Woods Hole. At the meeting, Mr. Lamson plans to propose that the boat line pursue federal grants to refurbish the ferries Eagle and Nantucket, to renovate the seasonal ferry terminal in Oak Bluffs, and to improve the SSA repair facility in Fairhaven.

In reviewing the numbers, Mr. Lamson said the number of passengers carried on the ferries directly affects the boat line's earnings, in contrast to automobiles and trucks, which he said tend to provide a wash between revenues and costs.

The fall-off in passengers, along with rising fuel costs, came home to haunt the boat line this year, prompting across-the-board rate increases for the first time in several years.

A breakdown of the numbers shows that SSA ferries carried 2,098,037 passengers last year between Woods Hole and the Vineyard, a drop of 66,132 or 3.1 per cent. Ridership rose slightly on the Nantucket route by 2,808, or .6 per cent, to 511,798.

Boosting the Nantucket route was the resurgent fast ferry Flying Cloud, which carried 190,190 passengers. That translates into an increase of 12,547, or 7.1 per cent, despite a three-month layoff at the start of the year.

Automobile traffic on SSA ferries slipped 6,238, or 1.4 per cent, to 455,657. Cars carried on the Vineyard route fell 1.5 per cent to 385,305. Nantucket ferries carried 70,352 cars, a decline of .4 per cent.

Automobiles traveling under the excursion rate, a discount rate available to Islanders, fell 1.4 per cent on the Vineyard route while inching up .6 per cent on the Nantucket route.

In contrast, truck traffic rose 11.7 per cent to 141,620 on SSA ferries. The boat line carried 10,429 more trucks, an increase of 12 per cent, on the Vineyard route, and 4,368 more trucks, an increase of 11 per cent, on the Nantucket route.

The lion's share of the increased truck traffic came in vehicles less than 20 feet in length, accounting for 22.5 per cent of the increase. Mr. Lamson said that although the category includes a number of larger sport utility vehicles, he believes that the increase also reflects vans and pickup trucks used by tradesmen traveling to the Islands for more lucrative work than available on the mainland.

Overall vehicle traffic rose 2.6 per cent over last year to 596,277, reflecting an increase of 15,559. The overall traffic number still lagged behind years such as 2001, when the boat line carried 608,277 vehicles.