The damage to the Block Island ferry after it hit a Coast Guard buoy tender just north of Block Island yesterday.

The Providence Journal / Gretchen Ertl

A Coast Guard buoy tender and a Block Island ferry collided in thick fog about three miles north of Block Island yesterday afternoon, leaving a slight dent on the ferry’s bow and stories for its passengers to tell.

No injuries were reported, and neither vessel took on any water, Coast Guard Chief Petty Officer Amy Thomas, a spokeswoman out of Boston, said.

The multilevel ferry, named Block Island, was held up for a short time on the water until it could be checked out. Escorted by two other Coast Guard boats, it then continued under its own power to its Old Harbor port on the island, arriving at about 2:25 p.m.

The Coast Guard vessel — Morro Bay, a 140-foot buoy tender that had once served as an icebreaker — had been on its way back to its home port, in New London, Conn., from Newport.

The ferry had left Point Judith in Narragansett at 11:45 a.m. It was carrying 257 people plus its crew, the Coast Guard said, to the popular summer tourism location.

Visibility was about 200 yards at the time of the 12:15 p.m. collision, according the Coast Guard, but passengers described conditions as foggy.

At an evening news conference at the cutter’s home port of New London, Conn., the Coast Guard said it was not certain of the cause.

“At this point the circumstance as to how the crash occurred is part of the investigation. It is not available this early,” Thomas said. “We regret any inconvenience or distress this might have caused anybody on the ferry.”

Although no one was seriously injured, three people were taken to the medical center on Block Island, where they were treated and released, according to a ferry company spokesman.

The ferry was left with a 44-inch-long dent about 5 feet above the water line, Petty Officer Etta Smith said.

The incident is under investigation by the Coast Guard. William A. McCombe, the security officer for the ferry operators, Interstate Navigation, issued a statement about the incident, which he confirmed happened in thick fog.

When the ferry captain saw the Coast Guard vessel, McCombe said, he put the boat in neutral, then reversed and tried to back down. There was a “minor hit,” he said.

“The captain took evasive action to minimize a minor collision,” he said.

McCombe would not comment on who might have had the right of way, saying he didn’t want to interfere with an investigation by the National Transportation Safety Board.

However, he did say he thought it was “not so much a speed as a visibility issue.”

The 1,000-passenger capacity ferry was using radar at the time of the collision, McCombe said.

“That boat has made thousands of trips. This is the first incident that I know of like that involving that vessel,” he said.

Shortly before the collision, John Daveau said he heard the ferry sounding its horn and felt the ferry trying to slow. Then he saw the Coast Guard vessel cutting across the bow of the ferry. He said the ferry hit the cutter in the stern.

It was a bump “like hitting a dock,” said Daveau, who was sitting near the bow. “People started running for lifejackets. All the kids put on lifejackets.”

His wife, Michelle, said, “It took 20 years off my life.”

Brad Barco, 28, of West Greenwich, said he was riding on the top, outside level of the ferry close to the front with his girlfriend. He said the fog was thick and the ferry captain was blowing his horn every five minutes when they saw the Coast Guard cutter appear about 100 feet off the left of the ferry.

Barco said both ships tried to avoid an impact and were able to slow down quite a bit before they collided.

“I knew we weren’t going to be able to stop. I was like, ‘We’re going to hit this thing.’ And then it got closer, closer, closer. They started honking their horns back and forth. And before we knew it, we made impact,” he said.

John Austin, of Greenfield, Mass., was also aboard the ferry when it was hit, on the upper deck on the starboard side.

In a phone conversation with projo.com as he returned home on another ferry later yesterday, he said that the Coast Guard vessel “just appeared right out of the mist in front of us.”

“It took a few seconds for contact –– it was like everything was in slow motion,” he said, before the collision, which he described as “one glancing blow.” The ferry then glided to a stop.

The trip between Point Judith and Old Harbor is about 13 miles long, and usually takes about 55 minutes by ferry.

Shortly after the report of the collision, the Coast Guard sent out its traditional boating safety message in advance of the Fourth of July holiday weekend. It said in part:

“The Coast Guard advises all boaters and paddlers venturing out on the water this Fourth of July to be responsible and prudent mariners, to save the alcohol for when the trip is completed, and to maintain a constant safety vigil.”

While there were only minor injuries, there were a few cargo casualties. The ferry was carrying 55 cases of clam chowder, 1,000 pounds of shellfish and 2,000 pounds of produce including corn, lettuce and tomatoes that was destined for the plates of holiday visitors, said Steven Filippi, owner of Ballard’s Inn, a well-known restaurant and hotel complex at the ferry port.

He said he wasn’t allowed to get the food off the ferry until shortly before 5 p.m. Wednesday. By then, the mussels and steamers were bad, and he wasn’t sure whether the clam chowder had held up. Filippi said he was able to order replacement supplies to be delivered Thursday morning.

— With reports from projo.com staff writer Brandie M. Jefferson, Journal city editor Tim Murphy,staff writers Paul Davis and Donita Naylor and the Associated Press.