The Dunedin teenager presumed drowned in the Clutha River got into trouble as soon as he hit the water, police say.
Police divers are searching the river this afternoon, and will continue to search after the flows rise again when Contact Energy releases water from the Roxburgh Dam at 5pm.
Senior Sergeant Mike Cook, of Alexandra, told the ODT the divers had moved past the stretch of the river where the flows were the fastest, so would not be too badly affected by the higher flows after 5pm.
The missing 16-year-old boy and a friend jumped from the bank into the river about 2km below the Roxburgh dam around 3pm on Tuesday.
Snr Sgt Cook said the current was strong and the pair were quickly swept downstream in water too deep to reach the bottom.
"[The friend] has managed to get out. He saw his mate go under and that was the last he saw of him."
A police dive squad, boats and jetskis have been patrolling the river, but after two days searchers acknowledged there was little chance he had survived.
"Realistically we are looking for a body now," Mr Cook said.
He said police had been in constant contact with the family and they were also preparing for the worst.
While the dive squad today focused on an area 500-600 metres from where the youth went under, boats patrolled further downstream.
Contact Energy had reduced river flow during daylight hours to aid searchers, returning levels to normal overnight.
Mr Cook said the youth had been in the area for fruitpicking work and had family there.
