The latest stricken vessel being towed into Greencastle Harbour by the local Coast Guard lifeboat.
The Greencastle Coast Guard has been involved in its fourth sea rescue in 24 hours.
In the latest incident a small pleasure boat, with two men on boat, was towed to Greencastle Harbour after taking on water off the Inishowen coast.
The lifeboat had just returned to its station after an emergency call to assist another vessel which had reported an injured crew member of board.
The man was eventually airlifted by helicopter to Altnagelvin Area Hospital in Derry for treatement for a suspected broken arm.
Both vessels were among a number making their way from Scotland to Derry for the All Ireland Flleadh.
Speaking from the Greencastle Coast Guard slipway, where the latest vessel was taken at about 8.30pm last night, Charlie Cavanagh, officer in charge, said severe weather conditions had played a part in the incidents.
He said: “The sea is very rough out there. As regards the latest incident, we do not know how the vessel began taking on water, so we will have to look into it.”