SOUTHWEST HARBOR — The Coast Guard rescued four fishermen early Wednesday after the fishing vessel Lydia & Maya started taking on water about 40 miles south of Southwest Harbor.

The Coast Guard received a broken transmission at about midnight from a crew member aboard the vessel saying it was taking on water. A distress signal soon followed, indicating the crew was in the water, a Coast Guard news release said.

Coast Guard Station Southwest Harbor launched a boat crew, and Air Station Cape Cod launched a MH-60 Jayhawk helicopter.

The helicopter arrived at about 2 a.m. and found four people in a life raft shooting off flares and using a signal light. The helicopter lowered a rescue swimmer, and the fishermen were hoisted into the helicopter.

The Coast Guard said the Lydia & Maya’s crew suffered mild hypothermia and were taken to Bar Harbor airport for medical attention.

“The weather conditions were not ideal for searching,” Chief Petty Officer Aaron Clendaniel said. “The Lydia & Maya crew did a great job making sure their safety supplies were in good working condition, and that is what allowed us to find them so quickly.”

The fate of the 71-foot fishing vessel is still under investigation. The Coast Guard did not have the names of the crew members rescued Wednesday, a Coast Guard dispatcher said.

The Lydia & Maya lists Boston as its port of call, although the trawler has been regularly moored at the Portland Fish Pier over the years. It is owned by a Scarborough company, Lydia & Maya Inc. A man who answered the phone at Lydia & Maya Inc. Wednesday said he had no comment and didn’t know anything about what had happened earlier in the morning.

In July, the captain of the Lydia & Maya was arrested in Boston after allegedly threatening a Brunswick man with a machete. Police said Stephen Thuotte, 54, of Porter, held a machete against the neck of another man at the Boston Fish Pier. Thuotte was charged with assault with a dangerous weapon against someone 50 or older, a felony under Massachusetts law.

In 2013, the boat’s captain at the time, 47-year-old Martin Gorham, was lost at sea after falling off the fishing vessel in rough winter seas off Cape Ann in Massachusetts.