WINTERPORT — Researchers diving in the Penobscot River last week surveyed what they believe are the remnants of a Revolutionary War ship that sank more than 200 years ago.

After two summers of searching the river’s waters, crews from the University of Maine and Maine Maritime Academy have found a large portion of a wooden vessel near Oak Point. Relying on historical accounts, the researchers believe the remains are that of the Warren, the flagship of the Penobscot River Expedition of 1779.

As many as 35 ships from that expedition may have been abandoned, set afire or sunk as they were chased upriver by the British during the Revolutionary War. The remnants of one of the worst U.S. naval defeats remain submerged in the murky waters of the Penobscot.

On a sunny Thursday morning last week, divers took turns exploring the wreckage of what they believe to be the Warren. They used a video camera to record an image of what lies submerged near the river’s bank. The camera also beamed back a dark and fuzzy image to a video monitor viewed by researchers aboard the Alice, the command center for this mission. When the camera cooperated and focused properly, long wooden beams could be seen lying in the chest-high water.

The find has particular significance for University of Maine graduate student J.B. Pelletier. Not only does Pelletier’s master’s degree research revolve around the Warren but the North Haven, Conn., native grew up across the street from the homestead of Dudley Saltonstall, the ship’s captain and commander of the doomed mission.

“It’s pretty exciting … to put your hands on a piece of history,” Pelletier said Sunday, recalling last week’s dives. Reverence was evident in his voice as he described what he saw while slowly moving about the collection of timbers.

“It’s such a beautiful ship,” he said. “It’s great to have your hands on her.”

The Warren was one of 13 frigates that were built for each of the American colonies. If the vessel surveyed last week is the Warren, it will be the only one of the 13 to be found.

“I’m pretty certain it’s the Warren,” Pelletier said. “According to historical records, it’s right where it should be.” The pattern of beams found in the Penobscot about a mile upriver from the Winterport marina also matches what is known about the construction of the Warren, he said.

The only way to positively identify the ship would be to find guns or other artifacts that are known to have been on the Warren. Any search for such artifacts would have to be approved by the Navy, which technically still owns the ship which has lain submerged in the Penobscot for more than 200 years. Under federal law, the Navy is obligated to protect its historic shipwreck sites such as those in Winterport.

The Navy is working with the university to develop a plan to preserve the Winterport site. As part of that effort, Robert Neyland, an underwater archaeologist for the Naval Historical Center, joined last week’s mission. The center, which is responsible for maintaining sunken naval remains, helped sponsor the search for the Penobscot fleet through a $50,000 grant.

“We want to find out what is there and preserve it,” Neyland said as he oversaw the surveying of the Warren on Thursday morning.

In addition to fulfilling the Navy’s responsibility to preserve the sunken ships, Neyland said, the remains of the scuttled Penobscot Expedition could help fill gaps in knowledge about shipbuilding during the early days of the American colonies.

“If found, these ships are important historically to the Navy,” he said.

The Naval Historical Center will work with the university’s researchers to determine if the remains of the Warren should be excavated so that archaeologists can learn more about life in pre-Revolutionary War America.

Warren Riess, a marine archaeologist in the university’s history department, heads the search for the Penobscot Expedition. Last week’s find was another chapter in the long and tedious process of cataloging the remains of the failed expedition.

“Most of the time it turns out to be an old barge or a refrigerator, but this time we’ve definitely found a ship,” Riess said as he shuttled a group of reporters to the site where divers were surveying the wreckage.

Riess’ hesitancy is well-founded. Earlier in the week, his crew thought it had found the remains of a ship that was sunk during the War of 1812 off present-day Hampden. Divers were sent to investigate. They returned to the surface with fistfuls of coal. It turns out the sunken vessel was a coal barge.

Pelletier, who swam among the boat’s coal bins, was philosophical about that miscue. “If nothing else, that’s one more ship we can cross off our list,” he said.