A 42-foot sailboat that began taking on water Sunday morning  near the mouth of the Saco River had to be towed to port, the Coast Guard said.

Chief Mike Faivre said the two-man crew of September Morn issued a distress call around 9 a.m., saying their vessel was taking on water.

Sea Tow, a Portland-based marine towing service, responded. Its crew was able to pump out the water and towed the vessel to Spring Point Marina in South Portland, Faivre said.

He said the Coast Guard, which responded to the vessel in distress with its 47-foot motorized life boat, may never know what caused the leak. The two people on board the boat were not injured.