PORTSMOUTH — Last night, Bob Marshall and Allan Bearse each paid $25 to the owner of a private boat who brought them to town for a School Committee meeting and then returned them to their home on Prudence Island.

Those fees are about three and a half times the rate of $7 a day that the town pays the Prudence Island Ferry for each secondary school student it transports.

And the experience of Bearse and Marshall raises questions about whether the School Department can provide a cost-effective alternative to the ferry that also meets with the approval of the commissioner of education.

If it can’t, it does not have the option of closing the Prudence Island School, as it had planned to do in September, no matter what the effect on the school budget.

The School Committee voted last night to look into alternative transportation.

It also agreed to explore ways to secure Title 1 or other federal funds for the Prudence Island School to help lower operational costs.

When the committee voted last spring to close the school, it had an unreasonable expectation that its young students would take the ferry to and from the mainland to attend classes, according to Commissioner Peter McWalters.

The combination of the ferry schedule and bus service would keep elementary school children out of their homes for a total of 10 hours a day, parents testified during an appeal of the committee’s vote last June.

No matter what course the committee takes, island residents will continue to work on plans intended to keep the school open in the long term, Bearse said last night.

Marshall said, “We are committed to bringing the costs down.”

“We will move forward on an endowment” in the hopes that an annual contribution might reduce the amount of operating expenses borne by taxpayers, Marshall said.

Other ideas that have been presented by a Prudence Island School Working Committee include:

•The creation of a charter school (the state has a moratorium on new charter schools).

•The designation of the island school as a magnet school eligible for federal funds.

•Increasing the number of grades at the school, which now serves three elementary school students.

•Creating a new school district on Prudence Island, either separate from the town or under the aegis of the council, also has been mentioned, but Marshall said residents know such an option is not “doable.”

Another option to help reduce costs would be transferring ownership to a historical preservation organization, which would take over responsibility for maintaining the century-old one-room schoolhouse, the only one in the state.

Outside last night’s meeting, Bearse and Marshall said the Prudence Island School does not qualify for federal funds for low-income students because it is linked administratively to the Melville Elementary School.

The higher-income, suburban population of the Melville district masks the fact that Prudence Island is rural and poor, they said.

Both Marshall and Bearse are members of the Prudence Island School Working Committee. Bearse is also the father of one of the children attending the island school.

gmacris@projo.com