The Steamship Authority will lose the lease for its reservation office at the Martha’s Vineyard Airport, and is seriously considering closing the office.

The move is made necessary by the fact that the new owners of the so-called Beacon Building — Island Professional Realty LLC — have told the boat line they have other plans for the space, and will not extend the current lease beyond the end of January next year.

Tuesday’s meeting of the board of governors on Nantucket was presented with figures showing counter ticket sales at the booking office, which costs around $300,000 a year to operate, have been in steep decline in recent years.

In 2001, there were 47,000 over-the-counter transactions. That number declined to just over 30,000 in 2006, and last year it fell to under 18,000.

The office also handles some telephone sales, which have also declined, but not so sharply, from around 35,200 in 2006 to 31,350 last year, and deals with Islander issues relating to their profile numbers, for which statistics are not kept.

SSA general manager Wayne Lamson said the end of the lease at the current site “gives us an opportunity to take a step back and see if it’s something we still want to continue.”

He left open the options of whether the boat line should look for another site for its branch office, or whether it should centralize bookings at its year-round terminal in Vineyard Haven and seasonal terminal in Oak Bluffs.

Falmouth governor and board chairman Robert Marshall said consideration of the future for the reservation office should not happen without the participation of Vineyard governor Marc Hanover, who was absent from Tuesday’s meeting.

But Mr. Marshall also made it clear that he would like to see the office closed.

“My opinion is for $300,000 if we’re handling five people an hour on average, this is a no-brainer . . .” Mr. Marshall said, adding: “Given the success of the Web site and the ever-decreasing traffic through this office and the cost, there’s not much of a decision to be made.”

George Balco, chairman of the Steamship Authority port council and a delegate to the council from Tisbury, disagreed.

“My impression is that it’s very much Islanders, I mean year-round Islanders that utilize this service,” he said, adding: “I want to make sure that we are able to service this particular clientele, and continue to serve them well. I think it’s a big service and we ought to be slow in totally doing away with it.” Mr. Balco suggested canvassing the views of those who used the services of the office.

Mr. Marshall replied: “For $300,000 and five customers an hour, we could have somebody driving around to each of their homes.”

But Mr. Balco questioned the calculation of the costs of the office. Given that staff would have to be redeployed elsewhere, wage costs should not be included. Thus the real cost, he said, was the $24,000 in annual rent plus utilities.

The branch office originally was established because of congestion at the boat line terminals, but as more customers move to online booking, Mr. Lamson said, that has become less of a problem.

In other boat line news, the business summary presented to the meeting was not heartening. For the first four months of 2011, the SSA carried 3.3 per cent fewer passengers on the Vineyard run than for the same period last year. Bad spring weather was blamed for much of that fall.

The number of regular-fare cars carried was down too, by 4.5 per cent, although the number of Island residents making off-Island trips was up 1.7 per cent.

The number of trucks also was off, by 2.3 per cent.

Governors also reviewed preliminary schedules for next winter and spring, which vary little from this year. The winter schedule will begin one day later, on Jan. 4, and end three days earlier, on April 17. The last boat out of Vineyard Haven will be at 7:15, rather than 7:30 p.m.