Volunteer RNLI crew on the Portpatrick lifeboat John Buchanan Barr took part in Exercise Diamond, a multi-agency search and rescue operation on Sunday, September 23.
The exercise was designed to test the response in a simulated major maritime incident.
The operation was in Belfast Lough and involved RNLI lifeboats from five stations in Northern Ireland, as well as Coastguard and air sea rescue helicopters. It aimed to simulate a major incident involving a collision between a passenger vessel with 120 people on board and a commercial car ferry with 50 passengers and 23 crew on board.
In the scenario, the passenger vessel was sinking rapidly following the collision, and the people on board had been ordered to abandon ship following a mayday distress call.
The master of the car ferry also requested assistance after reporting that he could see life rafts and people in the water, and that his vessel was starting to list as a result of several trailers on deck overturning, trapping two people. Another trailer had caught fire.
Belfast Coastguard coordinated the air and sea search and rescue in which RNLI lifeboats searched for 100 casualties in the water.