The Ballyglass Coast Guard unit was called to assist, after a small sailing boat with two people on board overturned in the bay, just off Blacksod Pier yesterday afternoon.
A person on the shoreline who noticed what happened raised the alarm.
A local fisherman immediately responded and launched his boat, heading out to the stricken vessel.
The skipper of the sail boat managed to right his vessel and got the second person out of the water and back on board.
On arrival, the fisherman attached a tow-line to the sail boat and towed it back to safety.
The Ballyglass Inshore Lifeboat escorted both vessels back to the pier at Blacksod.
One of the crew of the sail boat was suffering from mild hypothermia, and was attended to by local Coast Guard members.
No further medical attention was required.
Ballyglass Coast Guard have commended the person who called the emergency services, and the fisherman who responded so quickly to the incident.