A teenager who drowned at Wentworth Falls lake last night was a "well-liked young man amongst his family and friends and peers", police said.
Police have identified the body of the teenage boy as Michael Ryall from Lawson.
Emergency services were called to near the spillway at the lake about 5pm on Wednesday evening and started searching for his body, which was found in the lake about 10.30pm and brought ashore.
Blue Mountains Local Area Command Detective Superintendent Darryl Jobson said 16-year-old Michael, known as Mikey by his friends, was fishing with his 15-year-old brother.
"They'd actually caught a fish, unhooked the fish and placed the fish on a rock near the water's edge. The fish has somehow managed to re-enter the water and appeared fatigued. Michael has then entered the water and a short time later has got into some difficulty," Supt Jobson said.
"His 15-year-old brother and another fishermen not connected with the brothers entered the water. They actually got to Michael and were able to take hold of him but unfortunately he could not be saved and disappeared under the water. Out of concern for their own safety his brother and the other fisherman had returned to shore."
Supt Jobson said Michael had stripped down to cargo trousers to enter the water, but police don't believe he had gotten tangled in anything in the water.
"Our thoughts and prayers are with the family and friends of Michael at this distressing time as they come to terms with such a tragic loss in these circumstances."
He said the HSC student was a fine young man.
"Michael was a well-liked young man amongst his family and friends and peers. He was a very fit young man, also loved, and had a passion for cricket and fishing."
The matter will go before the Coroner and is subject to ongoing police investigations. Supt Jobson said further inquiries would examine Michael's swimming proficiency, the temperature of the water and if Michael had any medical conditions, although he was not aware of any.
His death is not being treated as suspicious.