By and large, the 40-odd Islanders who came out for last night's forum on the Steamship Authority's new service model accepted the logic behind the proposal but questioned the details that will make it all work.

While the SSA board of governors won't vote on the proposal until August, the new model promises to reduce car traffic both on the Cape and to the Islands by focusing more on passenger service from New Bedford and committing to the use of high-speed ferries for both passengers and vehicles.

But like a fancy restaurant menu, there are no projected costs attached to the elements of the service model. Those figures and analysis are coming next week, said SSA general manager Armand Tiberio. At last night's forum hosted by the Martha's Vineyard Commission in the basement the Old Whaling Church, people wasted no time detecting pitfalls of the plan, from unknown costs to unreliable technology.

Warren Doty, a Chilmark selectman, fired one of the first shots, pointing out the poor track record of the SSA's new high-speed passenger ferry, the Flying Cloud, which began serving Nantucket last year. Under the new service model, a high-speed ferry for both passengers and vehicles would be built for the Nantucket run at a cost of between $22 and $27 million.

"Will high speed in the future vision work for the Islands?" asked Mr. Doty. "The Flying Cloud was not very dependable in its first year. How high-tech dependent are we going to be? Will it work trip after trip, and what is the cancellation record?"

Mr. Tiberio, who has pitched the switch to high-speed ferries as critical to the future of the SSA, acknowledged the problems with the Flying Cloud, but he stood behind the technology. "There were engine, fuel pump and turbocharger issues, but it was all covered by the warranty," he said. "The technology on the Flying Cloud, is it Star Wars? No. From a technology reliability standpoint, it's as reliable as any other vessel, and it will only improve over the years."

As for a proposed high-speed ferry combining freight, passengers and cars, there are hardly any being used in North America, Mr. Tiberio said, because there aren't many water routes of more than 20 nautical miles. Such ferries are more common in Europe, he said.

While the cost of that kind of ferry has a projected pricetag, the entire plan is still lacking one, and that fact made a number of people reluctant to give the model any consideration. "We need to know the costs," said Robert Lamb, an Oak Bluffs resident. And Cora Medeiros, the former Tisbury selectman, asked, "Who is going to pay for it?"

To be sure, this new model could turn on that issue alone. The SSA is already near its bonding limit of $50 million. Increasing the limit would mean going to state legislature for approval.

But Mr. Tiberio contended last night that the model would end up trimming costs through more efficient boats and fewer daily trips during the peak months between May and October. According to the plan, the number of ferry trips to the Island would be cut back from 32 a day to 27 a day over the next few years if the model were fully implemented. For Nantucket, the number would drop from 15 to nine trips a day.

While Nantucket's SSA governor Grace Grossman has criticized the service model for coming on too quickly and without initial review by the board of governors, Vineyard governor Riggs Parker has stood by Mr. Tiberio during several presentations of the model. Last night, Mr. Parker did not play the role of either skeptic or salesman. Rather, he simply invited Islanders to comment on the service model.

Much of the reaction was aimed not at elements contained in the model but at issues and details left out. David Pritchard of Edgartown was upset that the service model made no mention of efforts to bring the old ferry Nobska back into service from New Bedford. "It wouldn't cost the Steamship one dime of capital," he said, but the project needs SSA approval to be eligible for outside funding.

Mr. Pritchard took issue with Mr. Tiberio's market research results, stating that consumers had no patience for slow ferry rides. "For more than 50 per cent of the market, it has nothing to do with speed," he said.

The loudest reaction by far came from those who felt the service model focused heavily on the issue of people coming to the Islands, while neglecting the needs of Islanders to get off the Vineyard with as little hassle as possible.

Andrew Woodruff, a commissioner on the MVC, said that while the service model centered on the peak months, he was more concerned with the off-season between October and May. "I heard you speak a lot about people getting here," he said. "It's important to Islanders to get on a boat with convenience and ease. I was in standby for five hours on a Tuesday."

David Araujo of Oak Bluffs drove home the same point while offering up his own solution. "A lot of this model I support, and the Steamship has a good concept, but throw me a bone," he said. "Give us one boat a day for Islanders. Let us get off at six in the morning and let us come back at 7 at night. It's a damned shame that an Islander can go off and not come back."

Mr. Tiberio agreed that it will be a challenge to reduce the number of trips to the Vineyard, while making sure Islanders can leave when they want. "We need to improve our ability to get you people, the residents, back and forth," he said.

Marie Laursen of Tisbury made the matter even more local when she criticized the service model for not considering the impact on Vineyard Haven. "I don't see anything in this model that helps the port of Vineyard Haven deal with its intense traffic issues," she said, adding that the SSA should consider supporting shuttle and parking arrangements in Tisbury similar to the operation in Falmouth.

In a similar vein, Kate Warner, also a commissioner, raised the concern that a reduction in cars coming over on SSA ferries could still lead to traffic problems on the Vineyard. Both Ms. Warner and other pointed out the increase in the number of cars registered on the Island, many owned by seasonal residents. "In terms of traffic, we have met the enemy, and it's us," she said.

And she raised the issue of unintended consequences in West Tisbury, where transit buses converge in the summer. "Our historic center has become a bus terminal," she said. "We have a lot of work to do."

The service model's proposal to shift more freight over to private barge operators drew fire from Stephen Araujo, who runs a trucking business. "No company is going to want to take a $100,000 truck on a salt bath," he said. Plus, he added, consumers will suffer higher prices if truckers have to ride lengthy barge rides from New Bedford.

Finally, there were suggestions to incorporate new and better alliances with other transit providers. Tom Dunlop of New York city and Edgartown called for Bonanza Bus Lines to link up with the Schamonchi ferry in New Bedford. And Robert Douglas asked about the return of a rail service to Woods Hole. "A railroad back there," he said. "That would take some tires off the road."