The RNLI lifeboat was launched on the County Down lough on Thursday night.
A group of five men had got in to difficulty on a seven-metre yacht and were escorted back to safe water. No one was injured.
Seven others were rescued by the RNLI after becoming stranded on islands on the lough on Wednesday.
A second group of people have been brought to safety after getting into trouble on Strangford Lough in the space of 48 hours.