Each time a Steamship Authority boat has docked at Woods Hole or Hyannis over the past week or so, the captain has turned off the engines. In the time taken to load the vessel, the SSA saved five or six gallons of fuel.

Multiply the number of trips by the number of boats, and the boat line’s latest energy-saving measure makes a saving of more than $30,000 a month. Which sounds like a tidy sum, until you consider the cost of the fuel the boats still are burning.

For the month of May alone, the boat line’s treasurer, Robert Davis, reported to this week’s meeting of the boat line’s board of governors, fuel costs were $140,000 more than they had budgeted for.

This was despite the fact that as a result of previous fuel-saving measures, such as making fewer trips and slowing the boats to burn less, they used 29,000 fewer gallons of fuel.

So the latest energy-saving measure would cut only the problem by a quarter, all other things remaining equal.

And things are not remaining equal but getting worse. Mr. Davis told Tuesday’s meeting on Nantucket: “As of yesterday, crude oil was trading about $135 a barrel. This year’s budget was based on $90 a barrel.”

“We will continue to make fuel and energy efficiency a priority,” Mr. Davis said. But the question is how much further energy savings they can squeeze out. The SSA has slowed the boats, got the captains to turn off engines. They’ve done the energy audit, replaced the old light bulbs.

At Tuesday’s meeting, board members were given new data on the capacity usage of all SSA services. But it was at nearly 90 per cent for Martha’s Vineyard.

Nonetheless, the SSA is looking at cutting some freight boat runs from the previously-agreed fall schedule. Already they “consolidate” services — that is, cancel — some trips on a case by case basis when vehicle numbers on a particular trip are low.

But the scope for savings there is not great.

As the boat line’s general manager, Wayne Lamson, told the meeting: ”Our legislative mandate is to provide adequate service for the Islands. Based on our initial review of last year’s traffic levels we don’t see where we can make any significant changes to our operating schedules for this coming fall.”

He said if they stayed on budget for the rest of year — fuel prices being the big variable — the SSA would have a net operating income of about $3.3 million, or $700,000 less than budget projections.

“I see revenues increasing as well, so some of that increase in operating expenses will be offset by some of those revenues,” he said.

So far this year, passenger numbers are up overall by about 22,000, and vehicles are up by about 3,700.

But the margins are getting thin. At one point in the discussion of the difficult budgetary situation, Nantucket board member and current chairman H. Flint Ranney suggested it would be time “to worry” if operating revenues declined much below $3 million.

The worry is both short term — for the unforeseen pressures on the current year’s budget — and longer term — for the prospects next year and beyond.

In talking about the five-year outlook now being prepared, Mr. Davis told the governors: “Rate increases are going to be a continuing thing for the foreseeable future, and the board should be aware of that.”

This prompted Falmouth board member Robert S. Marshall to clarify “for the benefit of the press, rate increases are a consideration. We’re not talking now about establishing a policy of rate increases.”

But the fact is, unless fuel prices decline, that seems to be where the boat line is headed, if not again this year, then next.

For now, said Mr. Lamson later: “We are trying to weather this additional increase [in fuel costs] and see whether the price stays or starts to drop.

“It’s going to be interesting with the President’s remarks about opening up offshore drilling and other things as to what impact will happen,” Mr. Lamson said.

It might, he suggested hopefully, take some of the speculation out of the market.

That’s the thing, though. The boat line officials now, they privately concede, have done just about all they can to control fuel costs. They find themselves pinning hopes on things outside their control, like whether market speculators or Congress pay any attention to the President.

Or, even more imponderable, the weather. In the immediate future, Mr. Lamson said, a critical factor is sunshine.

“That’s what it will really come down to,” he said, “is the weather this summer.

“I think people are going to be staying closer to home this summer. I think day trips, within a gas tank of Woods Hole or Hyannis, is where they’ll come from. I think people will still be going to the Islands.”