The RNLI Peterhead were alerted to reports of a red flare on Saturday night.
The crew was so quick to attend that one of the rescuers was still wearing his pyjamas as he raced to the scene.
The volunteer crew launched Tamar-class lifeboat The Misses Robertson of Kintail at around 8pm to search for any vessels in distress.
After searching the mouth of the River Ugie and Craigewan rocks for more than two hours – and once satisfied there were no lives in danger – the volunteers eventually stood down at 10.30pm.
The lifeboat returned to the station at 10.45pm, where it was refuelled and made ready for service once more.
A spokesperson for the service stated: “The station’s crew had been enjoying their Saturday evenings, some of them even running to the station in pyjamas, when their pagers alerted them to the launch request.
“Once gathered, and having run through the briefing, the volunteer crew launched, in calm sea conditions, to start their search for any vessels in distress.
“The volunteer crew searched off the River Ugie mouth and Craigewan rocks without finding a casualty or any sign of a vessel.
“Once satisfied that there were no lives in danger, the lifeboat was stood down at 10.30pm and returned to the station at 10.45pm where she was refuelled and made ready for service.”
The team posted pictures of their escapade online, noting: “As you can see from the pictures, the crew attend no matter their conditions.”