A shortage of deck officers at the Steamship Authority could soon cause changes at the ferry line, officials said this week.

Four experienced Steamship Authority deck officers — licensed mariners responsible for safety and navigation aboard ferries — will not be reporting for duty this spring, potentially affecting the summer operating schedule, general manager Robert Davis told the boat line board of governors Monday afternoon.

“Late last week, we received word that some of the individuals that we had been counting on being there will not be able to sail with us this summer,” Mr. Davis said.

Only one of the officers has left the Steamship Authority entirely, Mr. Davis said, while one is on family leave and two others have learned they need medical procedures that will leave them unfit for duty until they recover.

“The individuals are very disheartened that they put us in this position, but as we told them, their health is more important,” he said.

The boat line is scrambling to reconfigure its early-summer schedule, which runs from May 18 to June 16, to accommodate the lack of deck officers, Mr. Davis said.

With overtime, he said, there may not be a need to cancel trips.

“It’s an expensive way to do it, but we just don’t have the bodies at this point,” he said.

The boat line has been working to promote existing crewmembers, Mr. Davis said, but that process also has hit an unexpected snag.

Over the past winter, he said, the SSA sent 10 employees to an eight-week training program in preparation for the U.S. Coast Guard’s deck officer licensing examination this spring.

In past years, a mariner’s new license would be issued within a week or so of passing the exam, Mr. Davis said.

“We’re hearing now that it’s taking 30 to 60 days for those licenses to be mailed out,” he said.

“There’s a distinct possibility we’ll have to make more [schedule] changes,” Mr. Davis said.

The Steamship Authority is far from alone in its plight: Deck officers are in short supply worldwide, director of marine operations Mark Amundsen told the board Monday.

“It’s a problem we’re going to be experiencing for years,” Mr. Amundsen said.

“I think we’ve been doing very well [to] keep our officers,” he added, citing cancellations on the Washington State Ferry system due to persistent mariner shortages in recent years.

Mr. Davis said the Steamship Authority will need to ramp up its training efforts, sending more people to the Coast Guard licensing course and starting earlier in the off-season.

“Now that we know about the licensing delay, we might want to look at starting this process this fall, if we can afford to send their bodies out,” he said, noting the eight-week absence from duty required for the training.

Among other business Monday, Mr. Davis reported that two of the Steamship Authority’s three recently-acquired offshore service vessels, to be renamed M/V Aquinnah and M/V Barnstable, are about to begin conversion work at Alabama Shipyard in Mobile, Ala.

Earlier this month, the board of governors voted to approve a $27 million contract to convert the two into freight ferries.

The boat line also has reached an agreement with Alabama Shipyard to convert the third offshore service vessel, renamed M/V Monomoy, for $18 million, Mr. Davis said.