Mountain rescuers used their two inflatable boats as part of a major operation to search for a man reported missing in Brothers Water.
The search began on Tuesday evening and continued into Wednesday when a body was found.
Patterdale Mountain Rescue Team was alerted shortly before 7pm on Tuesday after a call was made to Cumbria police expressing concern about the man, in his 30s and from Newcastle, who had gone into the lake to swim.
Rescue team volunteers joined ambulance crews, fire and rescue service members, Coastguard staff and police underwater search officers at the scene.
A Patterdale MRT spokesperson said the man disappeared from the view of his friends on the lake shore.
“A deputy leader and two team members were at base ready for a training evening mobilised within minutes to the scene, along with Patterdale fire service,” the spokesperson said. “At scene, a detailed search was immediately undertaken along the lakeshore.
“As further team members arrived the team’s two inflatable rescue boats were launched onto the water to assist with the search. As daylight faded the search was handed over to a specialist police dive team.”
Police said a body was found about 2.30pm on Wednesday. “Formal identification has not yet taken place,” Cumbria Constabulary said.
The incident involved 25 Patterdale MRT volunteers for 3½ hours.
The team added: “The team would like to remind open-water swimmers to take extreme care while swimming in the lakes and rivers in the current warm conditions.”
On Wednesday the rescue team went to the aid of a walker stuck on a ledge on Gowbarrow Fell.
Police alerted Patterdale MRT about 2.40pm after the woman, in her early 60s, got into difficulty trying to find her way down to the main road.
The spokesperson said: “On speaking to the female she was not injured but very scared and stated she could not move.
“A limited callout was initiated and four team members climbed up to the female where she was put on a rope belay system and helped back off the ledge to safety and walked off the fell back to Aira Force.
“She was extremely grateful for the team’s assistance and explained she had tried to find the way down and realised she could not go down or up at the location she had ended up at.”