The UK Coastguard said lifejackets had helped save the lives of the seven crew members.
The boat issued a Mayday call shortly after 2.30pm three miles off of Kinlochbervie.
A Coastguard helicopter, Lochinver lifeboat and Coastguard Rescue Teams from Kinlochbervie and Durness were sent out.
There is no doubt that the fact these crew members were wearing lifejackets went a considerable way to helping save their lives
The boat sank but a local vessel rescued the crew and took them to Kinlochbervie Harbour.
Three crew members were flown to hospital in Inverness by the Coastguard helicopter as they were thought to be suffering from hypothermia.
The remaining crew members were treated for the effects of the cold.
Scott Mackenzie, from HM Coastguard, said: “There is no doubt that the fact these crew members were wearing lifejackets went a considerable way to helping save their lives.”
