By MIKE SECCOMBE

It sometimes seems, when trying to get on or off the Vineyard, that the Steamship Authority ferries are always booked.

But that apparently is not right. There is persistent excess capacity, and boat line senior managers have colored graphs and spreadsheets to prove it.

Today, when the SSA governors convene on Nantucket for their June meeting, they will have those graphs and spreadsheets in front of them as they begin talking about next year’s operating schedule, and possibly even the fall operating schedule.

There is no certainty where those discussions will ultimately lead, but given the pressure the SSA is under to cut its fuel consumption and given the skyrocketing price of oil, it is not out of the question that this could lead to some kind of rationing of services.

Already fuel prices have forced an increase in ticket costs. They have resulted in the boats being required to slow down so as to burn less fuel. SSA governors have considered and rejected the idea of a fuel surcharge. And as they run out of ways to boost efficiency, oil prices keep rising.

And management thinks it has identified in the capacity study a way to become a little more efficient. And that may mean a little less frequent — or it may not.

But it certainly will be a subject for discussion today.

Other matters up before the SSA governors look more straightforward, although also expensive.

The governors will hear a report on how phase one of the major reconstruction of the boat line’s Oak Bluffs terminal was completed just hours before the first ferry was to arrive for the season.

And they will be asked to approve a $4.5 million contract for the same construction outfit — RDA Construction Corps (this time in association with Pihl Construction of Boston), to do the second phase of the project.

Work is scheduled to begin in October and be finished mid-April, 2009.

SSA management will also recommend governors sign off on a contract for almost $2 million for dredging work at the Fairhaven maintenance facility by Cashman Dredging and Marine Contractors (the amount is $1.9 million) and another $250,000 contract with Apex Environmental Inc. to manage the project.

And the city of New Bedford will receive about $750,000 to dispose of the dredged materials.

In other boat line-related matters, the SSA and Martha’s Vineyard Chamber of Commerce have begun looking for volunteers to carry out customer surveys aboard the boats, asking people what they think not only of SSA service, but their overall Island experience.

Volunteers, a press release said, will do the research between July 1 and August 23. And they will be given complimentary ferry passes, plus the chance to win an unidentified grand prize giveaway.

The volunteers will be issued with surveys kits, uniform white polo shirts and identification.

So they will be easy to recognize, for those who wish to record their views on the boat line’s quest for efficiency gains.