PORTLAND — U.S. Rep. Chellie Pingree and her husband, Donald Sussman, were aboard a water taxi involved in a crash with another boat off Portland Harbor on Saturday night.

Sussman suffered head injuries and was treated at Maine Medical Center and released. Sussman also suffered minor cuts and bruises, according to Pingree’s spokesman Willie Ritch.

A passenger on the recreational vehicle, 50-year-old Sally Handy of Boulder, Colo., remained in fair condition at Maine Medical Center on Sunday afternoon.

Pingree and Sussman, along with two other couples, were returning on the Bay Express, owned by Portland Express Water Taxi, from a wedding of a former staffer on Great Chebeague Island, when it collided with a recreational vessel, Miss M, a 20-foot Grady White, near Fort Gorges, Coast Guard Lt. Scott McCann said.

The South Portland Coast Guard station responded with the Portland Fire Department to a call at approximately 10.30 p.m., and they were on the scene within 15 minutes, McCann said.

Handy, the most seriously injured of those involved in the crash, suffered head injuries and was taken by ambulance to Maine Medical Center, he said.

Also injured was Jacqueline Potter, 66, of Portland, a former Pingree staffer, who was treated at a local hospital and released.

Pingree’s chief of staff, Jesse Connolly, 35, and his wife, Nicole Clegg, 43, spokeswoman for the city of Portland, along with Potter’s husband, William Black, 66, were also on board.

Pingree was not among those taken to a hospital.

McCann said the operator of the taxi, whose name has not been released, voluntarily submitted to an alcohol test, which showed no alcohol in his system.

Alcohol breathalyzer results were also negative for the operator and owner of the recreational boat, Christopher Pizey, 51, of Peaks Island, McCann said.

“My husband and I want to thank the quick work of the Coast Guard who was on the scene within minutes and the marine division of the Portland Fire Department who treated my husband and the others who were injured,” Pingree said in a statement released Sunday morning. “From the moment they arrived, we knew the injured were getting the best possible care. Although it was a scary night, it could have been much worse if it weren’t for the skill and dedication of everyone who responded to the accident.”

The Bay Express was safely moored at Dimillo’s Marina in Portland, and the Miss M was safely moored at Portland Yacht Services.

Maine Marine Patrol Officer Scott Couture said Sunday that the bow of the water taxi struck the port bow of the Miss M.

McCann said the weather Saturday night was “pretty good as you can get,” and was likely not a factor. The Coast Guard and Marine Patrol continue to investigate the two vessels’ speed, location in the channel and whether their navigational lights were on, he said.

“If they find somebody negligent for not following a law, I would imagine there would be charges,” he said.

No one involved fell into the water, which McCann said made responders’ jobs easier.

“There would have [been] a different outcome if people had gone into the water,” he said.