The Sankaty ferry was back up and running Monday after a crew shortage caused the Steamship Authority to cancel all of the freight ferry’s trips on Sunday. 

The U.S. Coast Guard has certain manning requirements for boats and one crew member who called out of work could not be replaced to make sailing possible, said Steamship Authority spokesperson Sean Driscoll. 

Mr. Driscoll said he could not give the crew member’s position, but each vessel needs a certain number of captains, pilots and seamen to run. The Steamship Authority tried to find a backup but was unsuccessful. 

The cancellations came the day before schools went back into session after a weeklong break. Some customers were able to be put on other boats, though others did leave their cars on the mainland and traveled as walk-on passengers, Mr. Driscoll said. 

The Authority was allowing those customers to park for free in the Palmer avenue lot. 

The Sankaty resumed service on Monday with its 6:30 a.m. scheduled trip from Woods Hole. The ferry usually makes a 5:30 a.m. run from Vineyard Haven as its first trip of the day, but construction at the Island terminal suspended that service. 

Mr. Driscoll said he had seen questions on why the Steamship Authority didn’t have a back-up crew available for these types of crew shortages. But the ferry line needs to make financially prudent decisions, he said. 

“We can’t just pay people to sit around waiting,” he said.