Nantucket banned construction two weeks ago. Towns on Martha’s Vineyard followed three days later.

But a few miles across the Sound in Woods Hole, Steamship Authority officials said work will continue as planned on the new, $70 million shoreside terminal reconstruction project. And all proper precautions are being taken, they said.

“If there ever was a definition of an essential government project, I think getting a slip constructed at Woods Hole would probably fit it,” SSA communications director Sean Driscoll said this week.

The massive, six-year project that began in 2018 entails the phased demolition of all the existing waterfront structures the SSA uses in Woods Hole, including replacement of three ferry slips and construction of two passenger loading piers, along with stormwater improvements.

Work is being done slip-by-slip during the off-season so as to not interrupt summer service, with only one slip rebuilt at a time. The general contractor for the project is the Quincy-based construction company Jay Cashman.

Even during the winter — and before the coronavirus pandemic — construction work on the slips has affected ferry service to the Island. Ferries have clipped work barges, and the tight spacing for the one or two available slips has forced captains to take extra precautions. Weather or mechanical issues have caused double the number of cancellations, due to the availability of only one slip in Woods Hole.

Now, with a tight construction deadline and summer on the horizon, SSA senior managers said they had no choice but to continue work on the project despite the spread of Covid-19. And while ridership has plummeted recently and the future remains unknown, the boat line needs to prepare for the summer ahead, whatever it might bring.

“Operationally, even if we end up looking at schedule modifications going further into the year . . . [the Woods Hole project] becomes a hindrance by the limit of work being as far out as it is,” SSA general manager Bob Davis said this week, speaking to the Gazette by phone. “It affects the traffic flow and things like that. We need to get that taken care of.”

Mr. Davis said the goal is to have winter work completed by mid to late May. He said the project is still on schedule, and that the pandemic has not affected expenses or manpower.

The statewide stay-at-home order classifies construction on public works and infrastructure projects as essential, with proper safety precautions.

And extra precautions have been taken. At a port council meeting Wednesday, project manager Bill Cloutier described the work site as a “postage stamp,” expressing concerns about social distancing. But Mr. Davis and Mr. Driscoll said Cashman crew members are adhering to social distancing, despite tight quarters and even tighter deadlines. On March 30, the crew took a day off to re-familiarize themselves with the required health and safety practices ordered by Gov. Charlie Baker. And Mr. Driscoll said the crew are securing the site daily, as if they were not coming back for several weeks.

“If there was something that happened suddenly, the site would be secure and we could feel confident that it was fine to be left,” he said. “So they are taking that extra step.”

Mr. Davis said while some members of the crew drive to the site from distant locations, other subcontractors are based in Falmouth and Mashpee.

Work is also continuing on vessel maintenance at the SSA’s Fairhaven dock, with slightly altered schedules, Mr. Driscoll said. With the recent service reductions, the timetable for getting boats in and out of drydock has become a little easier to manage, and because of financial cutbacks, the boat line is not approving overtime for maintenance projects, he also said.

Currently, the ferries Governor and Island Home are in Fairhaven, while the Nantucket is in drydock in New London, Conn.

Meanwhile, in Woods Hole, the Cashman barge crew and undersea divers continue to work on inserting monopiles, fabricating the slip’s utility platform and beginning the electrical work for the passenger platform. Work on passenger canopies is slated to begin next week.

The greater hope is to hope is to have summer sun — and passengers — to shade.

“We need to be at full capacity,” Mr. Driscoll said. “It’s hard to predict the next couple of weeks, to say nothing of the next couple of months. But if we don’t finish it now, when would we finish it? It’s not a half-finished house that we can get back to whenever we want to. This is something that needs to get done. The more we are able to proceed as planned the better off for everybody.”