The second day of a search for three boaters missing off the Maine coast will begin at dawn Sunday, according to the U.S. Coast Guard.

Rescuers spent most of Saturday looking for Charlotte Kirby, Nathaniel Davis and Wilfredo Lombardo in a 40-foot sailboat named Dove about 20 miles south of Mount Desert Island. Crews in boats and aircraft found no evidence of the vessel.

Emergency dispatchers on the mainland received a distress call from the boat at 3 a.m. Saturday, a Coast Guard spokeswoman, Petty Officer Nicole Groll, said in a telephone interview Saturday afternoon.

The callers told dispatchers they were on a boat and asked for help before the call cut out, Groll added.

The sailboat’s home port is the John Williams Boat Co. in Mount Desert. It departed Somes Sound, Groll said. The Coast Guard does not know when the boat left port, she added.

Rescuers began searching near the last known position of the mobile phone that made the 911 call, Groll said.

A 47-foot response boat from the Coast Guard station in Southwest Harbor, a helicopter from Air Station Cape Cod and a Canadian Coast Guard airplane are involved in the search.

On Saturday night, weather conditions in the search area included 5 foot seas with 20-knot winds, the Coast Guard reported. The air temperature was 34 degrees, and the water temperature was 52 degrees.

The search was called off after dark Saturday, but rescue crews intend to resume efforts at daybreak Sunday.